Time signatures and beat calculations

[Drammy]

Right, I have some gaps in my musical knowledge and I am hoping someone can fill them for me...

With time signatures I know that 4/4 means there are 4 instances of a 1/4 note per measure.

So 5/8 would mean that there are 5 instances of an 1/8 note per measure.

My question is this - does that mean that with a 5/8 time signature there are 5 beats per measure?

So with a tempo of 100bpm and a time signature of 5/8, is the following maths correct:

300ms per 1/8 note (ie beat)

and 1.5s per measure

I think I have but would appreciate someone confirming this or if not then explaining it in simpleton terms.

Thanks,

Drammy

[Juho L]

So 5/8 would mean that there are 5 instances of an 1/8 note per measure.

Yes.

My question is this - does that mean that with a 5/8 time signature there are 5 beats per measure?

Yes.

So with a tempo of 100bpm and a time signature of 5/8, is the following maths correct:

300ms per 1/8 note (ie beat)

and 1.5s per measure

Yes.

I think I have but would appreciate someone confirming this or if not then explaining it in simpleton terms.

Is "yes" a simpleton term enough?

[jasedee]

Is "yes" a simpleton term enough?
Can you dumb it down just a tad? ;)

[Drammy]

Thanks Juho...

[Drammy]

Sorry to bring this post back up again, but I still can't get my head around something. Problem is I am not too sure what it is I cannot get my head around...

Lets take a track with a tempo of 120bpm.

If the signature is 4/4 then each beat lasts for 500 ms... (correct?)

Now what...?

How long would each beat last for if the signature is 6/8? Sorry to be a school teacher but you must show your workings...



Ta,
Drammy

[jasedee]

Im gonna take a wild guess and say that nothing has changed...

Only now, you have 6 8th notes per bar (cant remember technical term), but your tempo is still 120BPM, so each beat still is only 0.5s

Am I right???

EDIT: Geez... I was so wrong!!!! Maths was never my strong point, so why am I studying acoustics at uni? Crazy I tells ya....

[Drammy]

I don't know, thats the problem.

Or has the fact that the 4th has become an eigth - made the length of the beat half?

It is all so confusilating (I've been playing Ratchet and Clank 2).

[Threlly]

just use timings based on the smallest reasonable measure
125ms

so, 125ms, 250ms, 500ms, 375ms(250ms+125ms)

get tricky, 62.5ms+125ms=187.5

187.5ms+250ms=437.5ms

try em, mix em right channel 250ms, left channel 375ms, feedback 187.5ms

etc etc etc

There is a simple formula for BMP to Milliseconds, do a Google.

[Tarekith]

Divide 60000 by your tempo to find the ms of a 1/4 note.

IE: 60000/132 = 1/4 note that's 454.54ms long

To find an 1/8th note, just halve the answer, IE 227.27ms

[Drammy]

Yeah I get all this guys,

Thing is I am writing a delay calc for myself in Visual Studio and I am trying to work out how to calculate delays on different time signatures...

I have all the 1/1, 1/2, 1/4, 1/8 and so on notes worked out for normal notes, dotted notes and triplets, but I don't quite understnad the effect of a time signature on a beats length.

Although my investigations are leading me to believe that it doesn't matter...


Anyone for input?

[Tarekith]

A 1/8 note in 4/4 is the exact same length as a 1/8th note at 5/8, provided the tempo is the same.

[Drammy]

Cool, thanks Tarekith - so th etime signature just tells us how many bars and measures...

Ta!

[Tarekith]

Yeah, the time signature just tell you the timing 'base' and most common divisions (more or less). The tempo and note divisions (1/8, dotted 1/4, whole note, etc) determine the actual length of each note.