Double Time and Half Time

[StonedSandman]

I can't seem to figure this out. Say for instance the sheet music will say Double time then in parenthesis have and eight note equals a quarter note. Does this mean that if a quarter note normally gets 50 BPM then in double time a quartar note would get 100BPM? And 25BPM in Half Time? Help is much appreciated as always.

[SwampDonkey]

Damn, I used to know all about this stuff, but I can't remember it...I think what you said is backwards, but I'm not positive though. Damn.

[Dax]

As per my understanding, when you enter double time, everything becomes sped up!

This means that notes would have to become half of what they were, compared to original, regular time. But when looked at in double time, they are still what they were originally. Uh....example time.

4/4 Time, 50 BPM.

You play a whole note. You have to hold it for four beats, and there are 50 of these beats in a minute.

Now, double time kicks in. The song has suddenly become 100 BPM. The sheet still says play a whole note. So you play a whole note, and hold it for four beats. However...these four beats have been sped up (so that there can be 100 of these beats in a minute), and have become twice as fast as before, and therefore half as long.

So, compared to the original speed of the piece of music, the whole note is half as long, when it is in double time, even though it is still written as a whole note on your sheet.

So your sheet says play a quarter note. So you play a bunch of quarter notes. The page says "Double Time". And yet it still says play a quarter note. But, to accomodate for the double time, you have to play the quarter notes twice as fast as you did in the original, regular speed. So quarter notes in double time, would be eigth notes in regular time.