Third-Party Notices and Attributions

Application

PocketDJ (iOS, iPadOS, macOS, visionOS)

Publisher

[Publisher]

Effective date

[Effective date pending]

Contact

contact@pocket-dj.com

These notices are being finalised. A few details — the publisher name and effective date above, and items noted in place below — will be completed before release.

About these notices

This document is the inventory of third-party software, assets, models, and data that PocketDJ uses, ships, or redistributes — with the licence for each and the specific obligation that licence places on us. It is the source for the in-app Settings ▸ Legal ▸ Third-Party Licences screen.

Scope. Each entry states how the component reaches users, because the obligation changes with it:

• Ships — the component is included in the App Store binary.
• Redistributes — PocketDJ serves the bytes from its cloud services to a user's device. This is legally a distribution, not merely a use.
• Server-side — the component runs in PocketDJ's cloud services and only its output reaches a device.

1. Summary

2. Swift package dependencies (ship in the app binary)

PocketDJ has exactly one third-party Swift package. Everything else in the app is first-party — the Mix tab's DJ engine is a first-party AVAudioEngine graph.

2.1 ZIPFoundation

Obligation: MIT requires that the copyright notice and permission notice appear in all copies or substantial portions of the software. Because we distribute a binary containing it, we reproduce the notice in the in-app Third-Party Licences screen. There is no attribution-in-marketing obligation, no share-alike, and no patent clause.

Full licence text:

MIT License

Copyright (c) 2017-2025 Thomas Zoechling (https://www.peakstep.com)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

3. Apple frameworks with attribution or badge requirements

Apple's frameworks are licensed to PocketDJ through the Apple Developer Program Licence Agreement (DPLA), not through an open-source licence, so there is no licence text to reproduce. What they carry are branding and attribution conditions, summarised below.

3.1 MusicKit / Apple Music

Posture. Apple Music integration in PocketDJ is playback only. PocketDJ plays Apple Music content through MusicKit, rendered by the MusicKit APIs, using the user's own subscription. PocketDJ does not download, capture, record, store, or modify Apple Music content, and does not synchronise it with other content.

Obligations this imposes:

1. Badge and link. Where PocketDJ surfaces Apple Music content — an album, song, artist, or playlist — it uses an Apple-supplied "Listen on Apple Music" badge or lockup, linked to that item on Apple Music. We may not draw our own badge. Only one badge per context.
2. Artwork must not be altered. Artwork returned by MusicKit may not be cropped, recoloured, overlaid, or composited.
3. Naming. "Apple Music" is used per the Identity Guidelines in the App Store description and in-app copy; PocketDJ is not presented as an Apple product or as affiliated with Apple.
4. No pre-add badge in conjunction with MusicKit — that is an affiliate-terms violation.

3.2 ShazamKit

Obligation: matching against the Shazam catalog and displaying the returned song metadata requires that we provide a link to that content in Apple Music, in accordance with the Apple Music Identity Guidelines. That link is mandatory.

The "Powered by Shazam" lockup or Shazam icon is optional — it may be used to promote the recognition service but is not required. If it is ever used in marketing material it goes through Apple's approval requirements. We do not currently use it and have no plan to.

3.3 SF Symbols

Obligations: SF Symbols may be used in apps running on Apple platforms. They may not be modified, may not be used to create a derivative or lookalike icon set, may not be used in app icons or marketing, and may not be reproduced outside Apple platforms. PocketDJ uses them unmodified as UI glyphs only, which is inside the grant. The PocketDJ app icon is first-party artwork and contains no SF Symbol.

3.4 Apple sample code

PocketDJ adopts the assistant-schema entity and intent shapes from Apple's WWDC26 sample "Integrating your music app with Apple Intelligence" (CosmoTunes) — the audio song / album / artist / playlist entities, the play-audio and add-to-playlist intents, and two enums. Apple sample code is distributed under the Apple Sample Code Licence, which permits use and redistribution in compiled form and requires that Apple's copyright notice be retained. PocketDJ retains that notice.

4. Bundled and redistributed assets

4.1 GeneralUser GS SoundFont — the virtual-instrument packs

This is a redistribution, not a use. We serve the file to other people's devices, and the licence has to be read against that posture.

Obligations, and how we meet them:

1. Commercial use of the bank is expressly permitted. "You may use GeneralUser GS without restriction for your own music creation, private or commercial… Please feel free to use it in your software projects."
2. The licence imposes no formal attribution requirement. Read strictly, v2.0 contains no "you must credit" clause. We credit anyway — the manifest carries an attribution string that the Instruments screen renders.
3. Do not hot-link the author's downloads. The licence asks that redistributors either link to the author's website or provide their own local copy. We host our own copy, which is the sanctioned path.
4. The bundled licence text travels with the redistribution. Not strictly required by the text, but it is the norm for redistributing a permissively licensed asset and it costs one file.

Full licence text — GeneralUser GS Licence v2.0:

*** GeneralUser GS v2.0.3 ***
***      License v2.0     ***

** License of the complete work **
You may use GeneralUser GS without restriction for your own music creation,
private or commercial. This SoundFont bank is provided to the community free of
charge. Please feel free to use it in your software projects, and to modify the
SoundFont bank or its packaging to suit your needs.

** License of contained samples **
GeneralUser GS inherits the usage rights of the samples contained within, all of
which allow full use in music production, including the ability to make profit
from musical recordings created with GeneralUser GS.

Many of the samples are original, but some were taken from other banks freely
(and legally) available on the Internet from various SoundFont websites. Because
GeneralUser GS originated as a personal project with no intention for
publication, I cannot be 100% sure where all of the samples originated, although
I do know that none of them came from commercially published SoundFont packages
or sample CDs. Regardless, many "free" SoundFonts available on the web may
indeed contain samples of questionable origin. My understanding of the
copyrights of all samples is only as good as the information provided by the
original sources. If you become aware of any restricted samples being used in
GeneralUser GS, please let me know so I can replace them.

This uncertainty may concern you if you intend to use GeneralUser GS in a
commercial software product. That being said, I have never received any
complaint regarding sample ownership since I published the original GeneralUser
GS back in 2000, and as far as I am aware, neither have any of the companies
creating commercial software products using GeneralUser GS.

** More info **
If you plan to feature GeneralUser GS on your own website, please do not link
directly to my download files. Either link to my website, or provide your own
local copy instead.

I hope you enjoy GeneralUser GS! This SoundFont bank is the product of many
years of hard work.

You can find updates to GeneralUser GS and more of my virtual instruments at:
http://www.schristiancollins.com

I can be reached via the contact page on my website here:
https://www.schristiancollins.com/contact

Thank you!
-~Chris

4.2 Sample packs, loop packs, drum kits

None. PocketDJ ships no sample library, no loop pack, and no drum kit. The Performance tab's samples, loops, slices, and cue points are all created by the user from their own audio. The only instrument content we distribute is the GeneralUser GS bank in §4.1.

4.3 Fonts

None. The app uses system fonts only, which carry no attribution obligation on Apple platforms.

4.4 Icons and app artwork

The app's icon and accent assets are first-party. UI glyphs are SF Symbols (§3.3). No third-party icon set — no Font Awesome, Feather, Material, Noun Project, or similar — is present.

4.5 Bundled audio

The one bundled audio file is a test fixture used by the Studio unit tests, not user-facing content.

4.6 Demo or bundled catalog content

A small metadata fixture is used for tests — metadata only, no audio. If a first-run demo experience with playable audio is added, every demo track will carry a licence entry with a source before it ships.

5. Server-side software and ML models

These components run in PocketDJ's cloud services, and only their output — stems, BPM / key / beat-grid analysis, transcripts — reaches a device. Running a model as a service is a different exposure from shipping its weights in an app.

5.1 Demucs — pretrained model weights (htdemucs)

The Demucs source code is MIT-licensed (§5.2); the pretrained model weights are licensed separately. The project's author states directly that:

"The model weights are not covered by the MIT license, and are provided only for scientific purposes."

This restriction traces to MUSDB18, the training corpus: it is provided for educational and academic purposes only, and a substantial portion of it (the MedleyDB tracks) is licensed CC BY-NC-SA 4.0 — non-commercial, share-alike. The non-commercial restriction on the training data is what confines the resulting weights. The Demucs LICENSE file is the MIT text for the software; it is not a grant for the weights. The weights are used server-side and are not distributed to devices; only separated-audio output is returned.

Full licence text (Demucs code — MIT): see §5.2.

5.2 Demucs — source code

Obligation: reproduce the copyright and permission notice. There is no obligation on the output of the software and no share-alike on separated audio — the constraint on our use comes entirely from the weights (§5.1), not from the code.

MIT License

Copyright (c) Meta Platforms, Inc. and affiliates.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

5.3 faster-whisper

Obligation: reproduce the notice. MIT imposes nothing on transcripts the model produces, and no attribution is required on generated text. The transcript being unencumbered by the model licence says nothing about the underlying song lyrics, which are a separate copyright owned by publishers (§7.5).

5.4 CTranslate2

Obligation: reproduce the notice.

5.5 OpenAI Whisper — model weights

Obligation: reproduce the notice. OpenAI released Whisper's model weights under MIT — commercial use included, with no output restriction.

5.6 librosa

Obligation: reproduce the copyright and permission notice.

ISC License

Copyright (c) 2013--2023, librosa development team.

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

5.7 PyTorch and the scientific-Python stack

Demucs pulls in PyTorch (BSD-3-Clause, © the PyTorch contributors / Meta), and librosa pulls in NumPy (BSD-3-Clause), SciPy (BSD-3-Clause), soundfile (BSD-3-Clause), audioread (MIT), and numba (BSD-2-Clause). All are permissive, all require notice reproduction, none imposes anything on output.

5.8 FFmpeg

Why the distinction matters: the copyleft obligations of both LGPL and GPL attach on distribution. We do not distribute FFmpeg — it is installed independently on the worker machines and invoked as a subprocess, and the output files it produces are not derivative works of FFmpeg. On that posture there is no source-provision obligation and no obligation on the app.

Two things would change that: bundling an FFmpeg binary or library into the app, or shipping a worker image that contains it to a third party. Neither is planned.

6. Web application dependencies

PocketDJ began as a progressive web app, and the web client is served alongside the native apps. Its runtime dependencies, versions, and licences, resolved from the installed tree:

hls.js is the one that is different. Apache-2.0 requires more than MIT does: retain copyright, patent, trademark, and attribution notices; include a copy of the licence; state any changes made to the files; and preserve any NOTICE file content in distributions. We make no changes to it, so the practical obligation is licence text plus notice preservation.

Build-time-only dependencies (Vite, TypeScript, Vitest, Playwright, and their trees) are not distributed and carry no notice obligation.

7. Data sources requiring attribution

PocketDJ's catalog is metadata — album and track names, artist, genre, release year, tempo, and key. It draws on several third-party services, each with its own attribution terms. Audio that a catalog entry may reference is separate infrastructure.

7.1 Apple — iTunes Search API

Obligations, stated as Apple states them:

1. Attribution. Content from the API must be attributed — for promotional content such as song previews, Apple's language is that it be identified as "provided courtesy of iTunes."
2. Badge adjacency. API-derived content must sit near an approved badge that links directly into Apple's store or Apple Music. This is the same badge obligation as §3.1.
3. No caching of artwork. Apple's terms permit artwork that is "streamed only, and not downloaded, saved, cached, or synchronized."
4. No independent entertainment value. The content must serve a promotional purpose, not stand on its own as the product.
5. Rate limit. Roughly 20 requests per minute, per calling identity.

7.2 Discogs

Obligations:

1. Descriptive User-Agent. Discogs requires a descriptive User-Agent identifying the client; PocketDJ sends one.
2. Rate limit. Unauthenticated access is roughly 25 requests per minute; our indexer throttles to a single shared lane well inside it.
3. Data vs. images — the distinction that matters. Much of the Discogs database is released CC0, which permits commercial use with no attribution required. Images are not CC0. Discogs hosts user-contributed images and does not own most of them; its terms restrict transferring "restricted data" to third parties and using it commercially.

We credit Discogs voluntarily even though CC0 does not require it.

7.3 MusicBrainz

Obligation: the artist–area relationship is core data and therefore CC0 — no attribution required, commercial use permitted. We credit MusicBrainz and the MetaBrainz Foundation anyway.

The trap to avoid: the non-core portion of the database is CC BY-NC-SA 3.0 — non-commercial. If the indexer is ever extended to pull tags, ratings, annotations, or other non-core fields, that data cannot ship in a commercial app without a MetaBrainz commercial licence. We keep the MusicBrainz surface at core data only.

Attribution text: "Includes data from MusicBrainz, licensed under CC0."

7.4 Wikipedia (English) — CC BY-SA 4.0

CC BY-SA has two mandatory conditions:

1. BY — attribution. Credit the source, link the licence, and indicate whether changes were made.
2. SA — share-alike. Adaptations of the licensed material must be released under CC BY-SA 4.0 or a compatible licence.

The honest nuance, because it cuts both ways. Much of what we extract — a release year, a genre, a track title, a duration — is fact, and facts are not copyrightable in the United States, so a pure-facts extraction arguably never triggers CC BY-SA at all. Two reasons not to rely on that alone: a track listing is a compilation whose selection and arrangement may attract thin copyright, and in the EU the sui generis database right protects substantial extraction regardless of originality; and attribution costs one line of UI while losing a CC BY-SA argument costs the licence entirely.

What discharges it: an acknowledgements entry naming Wikipedia, linking https://creativecommons.org/licenses/by-sa/4.0/, and stating that content was adapted — better still, rendering each album's source list on the album card so the credit sits next to the data it describes. PocketDJ's data extraction is confined to factual fields so that no Wikipedia prose reaches a shipped field.

7.5 Lyrics

Lyrics shown in PocketDJ are machine-transcribed on our servers from audio (see faster-whisper, §5.3). The underlying musical composition is a separate copyright owned by its publisher, unrelated to any recording right, and neither scraping a lyrics site nor machine-transcribing a vocal creates a licence in it. No third-party lyrics licence is claimed, and there is nothing to attribute here — this row exists so that the absence of a lyrics credit is not mistaken for an oversight.

7.6 Web search

A general-purpose web-search backfill supplied factual fields — artist, album, year — for albums the structured sources could not match. These are facts rather than copied text, and carry no attribution obligation.

7.7 Apple — the "Apple Music (Local)" library index

PocketDJ can index the user's local Apple Music / iTunes library into a catalog of metadata describing Apple Music items. This is Apple Media Services-derived metadata and is governed by the same terms as §7.1 — attribution, badge adjacency, and use as promotional content adjacent to a purchase path rather than as a standalone catalog. The catalog identifiers it records are the join key used in-app to start playback through MusicKit.

7.8 single-synth — first-party synthesised metadata

Some single-track album records are synthesised by PocketDJ's own indexer rather than fetched from any third party. Obligation: none. The records are first-party; this subsection exists so the provenance list is complete.

8. Build tooling (not distributed — no obligation)

Listed for completeness. None of these is distributed, so none carries an obligation.

This document is provided for informational purposes and does not constitute legal advice.