What decides the time signature of a piece?

Question

I understand what makes 4/4 and stuff how it means four quarter notes; quarter gets a beat. But why do we need different time signatures of the same beat recipeint? I mean, I've seen pieces in 3/4 that would fit with 4/4, and why do we need 6/8 and stuff, why can't we just use all four's?

Answer 1

A time signature is determined by the meter of the pieces. Meter is all about the pattern of beats within a piece. Consider a waltz, one of the defining characteristics is that it is in 3/4 that follows the pattern 1)Strong, 2) weak 3) anacrusis:

http://www.youtube.com/watch?v=jHmgeo-Y0-4&feature=related

This cannot be in 4/4 because it would throw off the relationship of beats in the music vs. those on the page. Sure you could write it out as if it were in 4/4, but then the musical beats you heard wouldn't line up with what was printed on the page.

Telling composes to write everything in 4 is like telling a painter he can only use a particular shade of blue for all his paintings. Eventually that just gets boring.

Answer 2

Technically any (?) meter can be written as 4/4...



6/8 could implicate two sets of eighth note triplets. 5/4 could fit into 4/4 if the five notes were grouped as 5 pentuplet quarter notes. 3/4 could fit into 4/4 if one whole note was split into three triplets (which would actually be 3/2). While the underlying feel *could* be presumed as four quarter notes. But why? What if the composer wants the the feel to be 3 beats instead of 4 beats per measure? Besides, writing music in such a manner would be an inconvenience for the performer to read notation with a bunch of polyrhythms and irregular groupings when it's not necessary and audibly unnoticeable.



4/4 implicates there's a strong pulse every four beats, 3/4 implicates there's a strong pulse every 3 beats, 6/8 implicates there's a strong pulse every six beats..so therefore the time signatures are different.

Answer 3

That's quite impossible, to fit 4 4 with 3 4? Imagine a Viennese Waltz or a Mazurka in 2 4, or a Habanera rhythm in 3 4. That's quite impossible.



It defines whether the piece is melodic or rhythmic (dance-like) OR the number of accented notes per measure. Cut time is similar to Common time when it comes to notation BUT is way different with the number of accented notes per measure. In 6 8 (compound equivalent of 2 4), there are two accented notes. And similar stuff.