Originally Posted by mgpt6
Many early audiophiles said we needed 3 channels (left,center, right) but vinyl could only handle 2 channels that is why we got 2ch. stereo in the late 50s
True dat: when Bell Labs started experimenting with "stereo" in the late 1930s, it was 3 channels. The first movie to use 3 speakers across the front was Disney's 'Fantasia'
, which was 99% music (for those who think the centre channel was intended for dialogue). Unfortunately, there was no suitable delivery media at the time, so stereo ended up being 2 channels.
As for "how many channels is best for music", I say the more the better. Capture and mix using as many discrete channels as logistics allow. Downmixing can be done later to match the channel limitations of various delivery media: 7.1 for BD, 5.1 for DVD, 2.0 for CD. Likewise, deliver using as many discrete channels as possible. Listeners can downmix to fewer channels in order to match their speaker layout (I'd prefer that to extracting additional channels).
For stereo to give the impression of a solid and stable wavefront, I'd want at least 3 channels (L/C/R). The rest (surrounds, height, etc) can be done using some sort of ambience extraction IF more discrete channels aren't possible. But the minimum for me would be 3 channels.