the only reason the ST was a popular choice with musicians, was because it had built in MIDI ports for controlling external synthesisers and the like... people got used to proper sequencing software, which would have been better if done on the amiga, had commodore opted to fit MIDI ports to the a500...
ST sound is terrible, and the programmers who use ST's dont do anything on the internal sound hardware... sadly not enough people knew about buying a serial -> midi conveter for the amiga, so the "pro" sequencers got left behind in favour of the Tracker-type progrmas such as Octamed on the amiga. As brilliant as these are (and where i started composing) the amiga sound chip (paula) was still only 8-bit, and not much good for studio work.
i think if C= had thought about it, they could have made up'ed paula to CD-quality (16 bit 44khz) instead of 8-bit, and stuck a midi in/out all on the A1200 - we would be looking at a lot more memories of Amiga use in the early days of many good musicians... as it is, history tells a different story.
ok, off-topic rant over...
cheers for the info on the birthday... and the amiga deserves to be celbrated!