Everything you hear here comes from running the cartridge's own sound engine (sonido_cada_cuadro, p13:6004, and sonido, p00:4E6B, which shares out the scores; the interrupt calls it at p00:410A with banks 13 and 14) on an emulated Z80, frame by frame at 60 per second, just as the game calls it. What the engine writes to the PSG is turned into sound with an AY-3-8910 (tools/musica.py). Each MP3 is the whole piece up to where it starts again, plus 8 seconds of the repeat fading out; those that do not repeat end where the engine ends.
The PSG writes have been compared frame by frame with those of openMSX (C-BIOS MSX1 japonés). In every frame the PSG ends up the same:
The timbre is not checked: it is a textbook AY-3-8910, not a recording of the emulator. The probes are tools/omsx_psg.tcl and tools/coteja_psg.py.
pide_sonido (p00:4E1F) and pide_sonido_ya (p00:4E34, without looking at the pause) save the banks at 0x6000 and 0x8000, map 13 and 14 and call sonido with the number in A: 0 silences everything, 0x01 to 0x7F is an effect, 0x80 to 0xF9 a tune (table at 0x743E) and from 0xFA up, orders (pause, resume). Before that, sonido_a_cero runs, leaving the copy of the PSG mixer at 0xBC. The sound RAM is at 0xE100-0xE1CD. Those that sound like another are published once, and those that last over 75 seconds without starting again are cut at 75.
The worlds' map tune (0x8A)
Asked for by L_45E8 y L_484F; la rutina musica_del_mapa pide la 0x88 en el castillo y la 0x8A en los mundos; lasts 32.4 s and starts again at second 0.4.
The castle's map tune (0x88)
Asked for by L_46EC y L_4835; is cut at 75 s (the piece goes on).
The tune at 0x4416 (0x87)
Asked for by L_4416; is cut at 75 s (the piece goes on).
The tune at 0x4363 (0x86)
Asked for by L_4363; lasts 22.9 s and starts again at second 11.7.
The room tune (0x8F)
Asked for by musica_de_la_sala; lasts 38.4 s and starts again at second 12.8.
The boss (0x90)
Asked for by musica_del_jefe; lasts 23.1 s and starts again at second 3.9.
The tune at 0x486E (0x8C)
Asked for by L_486E; lasts 8.5 s and starts again at second 2.6.
The special room (0x8D)
Asked for by L_48B7 y graficos_de_la_sala_especial; lasts 22.7 s and starts again at second 3.5.
The boss defeated (0x91)
Asked for by musica_del_jefe y L_5CEF; lasts 3.2 s and starts again at second 1.6.
The tune at 0x49F9 (0x92)
Asked for by L_49F9; lasts 12.4 s.
The tune at 0x4A35 (0x93)
Asked for by L_4A35; is cut at 75 s (the piece goes on).
The tune at 0x4547 (0x95)
Asked for by L_4547; lasts 7.1 s.
A track in the table (0x8B)
Asked for by ninguna llamada directa: sale de la tabla de música por un número calculado; lasts 38.9 s and starts again at second 6.9.
The tune at 0x4599 (0x8E)
Asked for by L_4599; lasts 1.6 s.
The tune at 0x499B (0x81)
Asked for by L_499B; lasts 3.3 s.
The jefe_vencido tune (0x84)
Asked for by jefe_vencido; lasts 2.6 s.