How many bits are there in a bar? This was a question posed by a student of music technology. “Hold on” I said, “you can talk about the number of beats in a bar, even the number of 'ticks' (PPQN or pulses per quarter note) would be relevant, but not bits.”
And very true. Talking about the number of bits in a bar has no relevance. It is like asking how many decibels there are in a banana.
But then I started thinking. Perhaps it is possible to put a figure on the number of beats in a bar. So I tried a few calculations.
Firstly let's assume CD-quality recording, which is still pretty much the standard, as using higher sampling rates and greater bit depths reduces the number of tracks and plug-ins that a system can cope with.
Also let's assume that the tempo is a 120 BPM (beats per minute) – a good average tempo. Not too fast, not too slow.
So now a bar lasts two seconds. There are 44,100 16-bit samples per second in a single track. So 44,100 x 16 x 2 = 1,411,200 bits in a bar.
But hang on, there will be more than one track playing at the same time. Modern recording styles often call for up to 48 tracks. So multiply this figure by 48. 1,411,200 x 48 = 67,737,600 bits per bar.
Converting this to a more meaningful expression, we can say that there are almost 68 megabits per bar in a typical multitrack recording.
Bet you always wanted to know that.