How do you exactly determine the main beat in a piece of music?

Question

Just from listening to a piece of music.. how do you know whether the main beat is a half note, quarter note, eighth note, or sixteenth note?

and also how do you tell the difference between duple meter and quadruple meter... they sound exactly the same to me!!

For example say you were hearing a piece of music that sounded like it had 15 beats in each measure .. (an odd time signature).. and the tempo sounds fast... there are really two possiblities, it could be an eith note time signature or a sixteenth note.. so it could be 15/8.. or 15/16????

Answer 1

The answer is involved. It involves feeling and counting the beats and listening to the phrasing of the melody. I will get back to you with more details when I have a little more time.
Promise!!
OK-the simple answer is that you can't EXACTLY determine what type of note is the beat note. Trained musicians spend a good part of their study on music theory,form and style. These things give you a chance to make a guess at how the music is put together.

However, I assume that you are talking popular music. In that case most (not all) popular music is written in 2/4, 4/4 and cut time (2/2) meters and sometimes 3/4 meter.

Standard song form is usually 32 measures long in an AABA format giving you 4 eight measure phrases. I you can feel and count the primary pulses (beat) in a phrase then you can make a reasonable guess as to the meter. For instance if you count 16 main pulses in the first phrase then your meter is probably 2/4 (although it could be 2/8, or 2/16 but not likely). If you count 32 beats, then your meter is probably (but not always) 4/4 . This is also your clue to duple or quadruple meter, although this also invovles heavy and light pulses which is another lecture!

The same piece of music written in 2/4 , 2/8 , 2/16, or 2/2 would all sound the same. The 2/4 signature simply tells you that there are going to be 2 quarter notes or something equal to two quarter notes in each measure, and usually (but not always) the quarter note is going to be the beat or pulse note.

If you are counting what sounds like 15 beats you are probably counting notes instead of beats or pulses. A meter signature with 15 of anything would be extremly rare, especially pop music.

This can be a difficult subject and sometimes you just have to go with a best guess. If you were able to write out the melody that would give you more clues - but that is a whole other subject.

Hope this helps in some way. Good luck.