!!!!help with varying BPM songs!!!! -ACID Product Family

Subject:!!!!help with varying BPM songs!!!! Posted by: HerbaList Date:9/10/2004 8:34:44 AM I've read the Sony solution on how to find the true BPM of a song where the BPM varies. But i dont understand it, its too complicated or maybe i'm jus slow...<-------maybe...lol but nah, was wondering if somebody could dumb it down for me, or give me some tips on what to do, also the same with ACAPELLAs...thanks alot firreal
Subject:RE: !!!!help with varying BPM songs!!!! Reply by: DKeenum Date:9/10/2004 11:21:42 AM Are you saying that the tempo (bpm) of the song varies (i.e. speeds up or slows down)? And... you have accapellas?
Subject:RE: !!!!help with varying BPM songs!!!! Reply by: rome Date:9/10/2004 12:12:59 PM Beatmapper helps. But if the song's tempo varies then you just have to make it fit with edits. There's no "fix tempo' button.
Subject:RE: !!!!help with varying BPM songs!!!! Reply by: JohnnyRoy Date:9/10/2004 2:41:19 PM > how to find the true BPM of a song where the BPM varies I assume you mean that the BPM is not steady, i.e., it varies slightly but the song really doesn’t have any tempo changes. I also assume by true BPM you mean average BPM. Metronome is right. There is no way to automatically fix the tempo. If you really want to do this in ACID, you could Beatmap the file and play it until its off beat. Cut it at this point and drop the file onto a lower track and start the Beatmapper at the place it went off. Keep repeating this until the end of the song. Then render all those tracks to a new track and delete the old tracks. What you have left should be pretty close to being on the beat. You might try that first to see if you can get away with it. If not, use Sound Forge. In Sound Forge you would slice the song into measures of four beats each and save them as separate wave files. Since the songs tempo varies, all these measures will be slightly different in length. Then add all the lengths (in seconds) of all the measures and divide by the number of measures. This will give you the average measure length. Let’s say this is 3 seconds. As Iacobus as shown us many times, the formula for calculating the BPM of 4/4 time is: 240 / length in seconds of a measure (i.e., 4 beats) = BPM. So in the case of a 3 second measure it would be 240 / 3 = 80 BPM. I think this is the true BPM you were looking for. Now how do you get the song into the true BPM? You need to make each measure equal the average. Load each measure back into Sound Forge and time stretch it to be the average length. Remember to preserve pitch when you time stretch. After all this is done, place all the measures in sequential order into a new wave in Sound Forge and save them as one big wave file. But before you save them, you want to set their ACID properties. They should be set to Beatmapped, with the average tempo you calculated. It’s very tedious, but it can be done. If you don’t have Sound Forge you can use the $69 Sound Forge Audio Studio. It has all the features you need for this job. As for Al Capalla, wasn’t he a gangster in Chicago during the 1920’s? ;-) ~jr
Subject:RE: !!!!help with varying BPM songs!!!! Reply by: MikeDee Date:9/10/2004 8:40:44 PM Uh-huh...and Al Dente was his dentist. Zzzzzzzzhhhhhhhh........... T D h é e è

> how to find the true BPM of a song where the BPM varies

I assume you mean that the BPM is not steady, i.e., it varies slightly but the song really doesn’t have any tempo changes. I also assume by true BPM you mean average BPM.

Metronome is right. There is no way to automatically fix the tempo.

If you really want to do this in ACID, you could Beatmap the file and play it until its off beat. Cut it at this point and drop the file onto a lower track and start the Beatmapper at the place it went off. Keep repeating this until the end of the song. Then render all those tracks to a new track and delete the old tracks. What you have left should be pretty close to being on the beat. You might try that first to see if you can get away with it. If not, use Sound Forge.

In Sound Forge you would slice the song into measures of four beats each and save them as separate wave files. Since the songs tempo varies, all these measures will be slightly different in length. Then add all the lengths (in seconds) of all the measures and divide by the number of measures. This will give you the average measure length.

Let’s say this is 3 seconds. As Iacobus as shown us many times, the formula for calculating the BPM of 4/4 time is: 240 / length in seconds of a measure (i.e., 4 beats) = BPM. So in the case of a 3 second measure it would be 240 / 3 = 80 BPM. I think this is the true BPM you were looking for.

Now how do you get the song into the true BPM? You need to make each measure equal the average. Load each measure back into Sound Forge and time stretch it to be the average length. Remember to preserve pitch when you time stretch. After all this is done, place all the measures in sequential order into a new wave in Sound Forge and save them as one big wave file. But before you save them, you want to set their ACID properties. They should be set to Beatmapped, with the average tempo you calculated.

It’s very tedious, but it can be done. If you don’t have Sound Forge you can use the $69 Sound Forge Audio Studio. It has all the features you need for this job.

As for Al Capalla, wasn’t he a gangster in Chicago during the 1920’s? ;-)

~jr