What is SG2?

Sound Generator 2 is a ZX Spectrum 48k beeper Tracker. It is running in a slim version of my ZX Spectrum True Color emulator. It has 8 track configurations: SG62A, SG62B, SG62C, SG62D, SG71A, SG71B, SG71C and SG71D. SG62A, SG62B, SG62C and SG62D consist of 6 note channels and 2 drum channels. SG71A, SG71B, SG71C and SG71D consist of 7 note channels and 1 drum channel. The configurations with a letter appended have 3 note channels combined to a single accord channel for data size optimization. Every note channel span over 3 octaves. The 2 first note channels from the left are an octave higher than the other note channels. The letter represents where the accord channel is placed. A,B,C and D has respectively the accord channel placed as the first, the second, the third and the fourth channel from the left. Note channels have 32 volume levels and the drum channel has 256 volume levels.