Music.
All 19 original music sequences: zone themes, boss battles, jingles and credits. Each repeating piece keeps its original intro and a verified game-driver loop. Finite pieces play once.
Recovery and loop notes
Music loop points come from repeated active-channel SMPS state, including the original tempo, note timers, stream pointers, modulation, loops and subroutine stacks. A second full transport recurrence is verified. The player uses Web Audio sample-based loop boundaries after the intro; it does not restart the intro at each repeat. Some exact driver periods span several melodic passes. The transport interval is original; FM/PSG oscillator phases are not proven identical at the recorded wrap. A three-millisecond correction at the playback buffer’s tail brings its final sample to the loop-start value and smooths that discontinuity. This browser-only de-click preserves the loop timing and intro; downloadable Ogg and WAV recordings are unchanged. Title Screen, Ending, Extra Life, Sonic Got Through, Game Over, Continue Screen, Credits, Drowning and Chaos Emerald are finite in the original sequences. Their repeat switch stays disabled.
The separate speed-shoes collection contains seven original E2-triggered tempo previews of up to 30 seconds. The eighth tempo-table entry, Extra Life, equals its normal tempo and has no duplicate. Previews play once: long fractional tempo phases have not been packaged as native loops. The source tempo table is retained. These excerpts stay out of the music-only global Radio playlist.
New recordings were rendered through Genesis Plus GX from the supplied, unchanged REV00 ROM. The matching Sonic Retro disassembly rebuilds byte-for-byte to this cartridge; names and source boundaries come from that exact build. No replacement soundtrack is used. Physical Genesis audio has not been compared, and overlapping gameplay mixes are not separate recordings.
Detailed catalog and hashes · Source and rendering provenance · Original SMPS/DAC data package · Sonic Retro disassembly