I was wondering if having a series of 16 step sequencers can power any song in 4/4 time. Since 16 steps = 1 measure. Let's say I take some classical sheet music, could it be converted to a series of 16 step sequence patterns?
Assuming the only sequencer you have access to is a 16-step sequencer, the answer is no: you cannot play absolutely any song with a 16-step sequencer without losing precision the moment you want to play triplets.
An example of a piece in 4/4 time that uses triplets is Franz Schubert's Impromptu Op. 90 No. 1 (D. 899/1) in C Minor. (Even worse, Schubert assigns 8th-note triplets in the left hand against dotted 8th note-16th note patterns in the right hand at several points in this piece.)
Today's sequencers (if not the ones that are trying to emulate 1970s technology!) typically have a timing granularity of 256 or more 'clicks' per quarter-note. No-one complains TOO much about this being insufficient to express their music!
But 16 clicks per measure is WAY too little. Even 16 clicks per beat can't cope with a simple triplet.