Subject:Tempo

Posted by: wize

Date:3/12/2000 1:39:00 PM

I have posted numerous messages about changing Tempo of
songs. I found a message that answered my question (thanks
for the help!! Not!). But when I change the value's in
the 'Edit Tempo' section... it does nothing to the wav ??

Where am I going wrong ? This is the main reason I bought
this software and so far I have been unable to use it!

Subject:Re: Tempo

Reply by: Kelly_S

Date:3/13/2000 2:32:00 PM

Hello Tom.

Unfortunately changing the Tempo will not really affect the sound..
It is used for measuring the amount of BEATS in a .wav file.

Here is an excerpt from our FAQ about Edit Tempo:

To use the Edit Tempo function, first make a selection in the
waveform display. The selection made should be equal in size to the
length of a beat or measure. The easiest way to tune a selection to
be exactly one measure long is to play the selection looped and
change the selection points until a constant downbeat is heard. In
other words you need to set up a loop of one measure to give Sound
Forge a frame of reference.
After you have a measure selected that loops properly, go to the
Special menu and choose Edit Tempo. The Start, End, and Length fields
will show you what you have selected. There is no need to change
these values or the Input format. The 2 important pieces of
information are:

Selection Length in Beats
This control specifies the number of beats in the current selection.
Changing this value will automatically change the Tempo in beats per
minute control.


Number of Beats in a Measure
Use this control to specify the number of beats in a measure when
selecting a measure (e.g. 4 for most pop music out there).

Once you have the above values correct, you should have a value in
the "Tempo in beats per minute" field which seems correct. If it
reads something like 240, you probably have twice as high a number in
Selection Length in Beats (i.e. 8 instead of 4). Pressing OK will
then assign the correct BPM to the file.

You will need to repeat this process on the file you wish to match
beats with to know what its tempo is as well.

Say you have 2 files, A and B, and you want to speed up file B so
that it will match the tempo of file A. After having made note of
file A's tempo, select file B and launch Time Compress/ Expand from
the Process menu. You will want to find the value under Final Length
which gives you the BPM equal or as close as possible to the BPM of
file A under Final tempo. Use the Preview function to select a mode
which works the best for the material you are Compressing or
Expanding.

After changing the tempo of file B, copy it to the clipboard (double
click to select the entire file, then right-click and select copy).
Drop the cursor on the end of file A at the spot you wish to overlap,
right click and select either mix or crossfade, depending on how you
want them to overlap and the transition to work. You may wish to use
our Graphic Fade to tailor these overlapping sections before you mix
them.


You could use the Time Compress/Expand feature to adjust the actual
tempo of the .wav file, this command is available from the "Process"
menu in Sound Forge. It allows you to adjust the tempo without
changing the pitch.
It will take a bit of practicing and getting used to, however, I
think you'll find it to be beneficial to what you are doing.

Thanks!


Tom wrote:
>>I have posted numerous messages about changing Tempo of
>>songs. I found a message that answered my question (thanks
>>for the help!! Not!). But when I change the value's in
>>the 'Edit Tempo' section... it does nothing to the wav ??
>>
>>Where am I going wrong ? This is the main reason I bought
>>this software and so far I have been unable to use it!