This is not meant to be an exhaustive list; rather, it's a personal list of artists and websites which caught my eye and which I might find myself going back to in the future.

Entries in bold are personal favourites.

Remember, if you want music fine-tuned for your project, you're going to have to pay for it.

• DOVA SYNDROME - popular royalty-free music repository in Japan, with many contributing artists; make sure to check the license for each file you download; if you're in Europe, using the YouTube channel may be an easier way to browse through their work.
• OpenGameArt - mixed bag quality-wise, some real hidden gems exist though; has a strong focus on using CC-style licenses.

OpenGameArt - My picks (CC0 licensed)

OpenGameArt - My picks (CC-BY licensed)

• Alcaknight - 100+ songs, piano-centric, with a visual novel vibe; must be downloaded from SoundCloud; CC-BY 3.0
• ISAo/AIRYLUVS - OGA-BY 3.0; more songs by the same artist available under other licenses
• OtoLogic - CC-BY 4.0
• Steven O'Brien - CC-BY 3.0; note that not all of the artist's music is Creative Commons

The licensing descriptions do not constitute legal advice. I am not your lawyer. Please verify with the website, as the license descriptions may be inaccurate, or the licensing terms may have changed.

• ASOBEAT - the Google Sheets contain free download links; credit required unless you purchase the lossless Bandcamp versions
• Ontama - 500+ songs; OGG/MP3 versions are available; credit not required.
• Peritune - 300+ songs; OGG/M4A versions are available for free for royalty-free use, lossless WAV versions must be purchased; credit appreciated but optional; premium BGMs available. (While the “about” page lists CC-BY 4.0 as the license, the other terms are contradictory.) Offers convenient (and free!) bulk downloads.
  • Warning: The rules seem a little contrived. Most notably, there is an expectation of not distributing the verbatim music files for commercial works, potentially including as asset files - this may rule out usage in f.e. video games unless some kind of DRM scheme is implemented.
• SLOS - English licensing terms (credit required, notification required, providing a copy of a finished commercial work required); premium licensing exists but not outside of Japan
• TAM Music Factory - around since 1998! MP3/OGG/MIDI versions are avaialble. Credit not required for non-commercial use, required for commercial use; no need to notify TAM since June 2021; some songs can have the credit requirement waived for a fee. Some types of content (18+, sensitive, etc.) are not allowed - check with the website.
• Wingless Seraph - mostly game-centric songs; credit required.

• Kevin MacLeod - if you've ever been to the Western Internet, you've heard his work. Has music for just about every occasion. Nobody got fired for using Kevin MacLeod BGMs.
• MusMus - credit required for royalty-free use, license can be acquired
• Ross Budgen - more experimental; credit required.

• shiru8bit - CC-BY 3.0; has a lot of chiptune music in atypical formats.
• Tobu Tobu Girl DX soundtrack - CC-BY 4.0; MML-like format for GB homebrew

• Battle of the Bits - chiptune community with CC BY-NC-SA licensing. This is quite more restrictive than the typical expectation for “royalty-free music”, but if you're working on a jam game or a homebrew game, you might find this restriction irrelevant.

• BlueSky! (Ryuji)
• Rengoku-Teien
• SAM Free
• Shiho+ (Liberty Music Room)

These contain more artists than my own, so…!

• LemmaSoft forums' royalty-free music list - made with Ren'Py users in mind