Open-license MP3 test music

The authors' source pages mark these recordings CC0 1.0.
License: https://creativecommons.org/publicdomain/zero/1.0/

Changes: re-encoded from original MP3 to 128 kbps, 44.1 kHz, mono; source/title/author tags added.
Validated by ffprobe and full ffmpeg decode. Device playback has not been tested.

Shinsei — Gichco (obscure music)
File: shinsei.mp3
Source: https://opengameart.org/content/shinsei
Original download: https://opengameart.org/sites/default/files/cda98e895139.mp3
SHA-256: 4f61404dafe15c527011da0f772cdcb3dd18baf4357f90910a978a6dc65d91a4

Revelation — Indieteur
File: revelation.mp3
Source: https://opengameart.org/content/revelation
Original download: https://opengameart.org/sites/default/files/Revelation_0.mp3
SHA-256: 38eead99ccc3dd64b0ca8886030885a9017c5174baeffde3b65f5350c819b9d1

Gem Popper Piano Tune — Mopz
File: gem-popper-piano.mp3
Source: https://opengameart.org/content/gem-popper-piano-tune
Original download: https://opengameart.org/sites/default/files/gem_popper.mp3
SHA-256: 2788550accf9c12ce2c0d8ed8d74a98a18da402a9a5d9e93b0cad752f66b6de0