What determines the time signature of a piece of music?



I know that most music comes in 4/4, but why? What’s preventing someone from just putting more bars into the sheet music and making that 2/4?

In: Culture

Nothing technically prevents it, but the emphasis changes. In 4/4 there is a hard emphasis on 1 and a soft emphasis on 3.

You could absolutely do that. In fact, with enough effort any piece of music could be written in any time signature. However, time signatures hold important information about phrasing and emphasis. In a 2/4 time signature, every other beat is emphasized. In a 4/4 time signature, you know to emphasize the 1st beat the most, then the 3rd, then the 2nd and 4th. In a 3/4 time signature, you emphasize every 3rd beat, and phrases tend to come in lengths of 3. So unless you were careful to annotate the sheet music to indicate that you really want 4/4-type phrasing despite the music being written in 2/4, the 2/4 version would sound subtly different when performed by professional musicians, and a theoretical 3/4 version would sound much different.

It’s called common time for a reason. It’s an even number of weak and strong beats, easy to count, and very prevalent. 3/4 is generally harder to “feel” for the layman tho 2/4 and 6/8 usually feel quite natural to most. Rhythm and accents can be used to express a “6/8 feel” in 2/4, 3/4, and 4/4. It’s feel a matter of interpretation and the artist’s’ original intention.

To answer the second part of the question, yes, a piece of 4/4 music could be expressed in 2/4, but that would cost more money in publishing(remember print pressing was time consuming and somewhat expensive compared to modern printing).

r/musictheory might help, just to say.

Carry on.

A time signature isn’t just about beats and measures, it has a stylistic component, where some beats are emphasized more than others. A 2/4 beat is very steady UP down UP down, while 4/4 is UP down up down UP down up down. It also determines where the notes break. A 4/4 piece might have a dotted half note followed by a quarter note, you can make an equivalent rhythm in 2/4, but it would be unusual.