Find tempo/BPM of a song

[ßßßßßßßßßßßßßßß]

Please explain how, I'm too stupid.

[Nineko]

if you have a midi, a fruity loops file or a module (mod, xm, it, s3m), it's really easy, you just need to use a decent software.
if you're talking about an mp3, you can use a BPM calculator. there are some of them around somewhere. they usually ask you for you to tap your spacebar while listening to the song, and they guess the tempo in this way. there was also a winamp plugin that could do that by itself, not sure if it's still around.

anyway, if you tell us the format of your song, I'm sure you'll get more feedback.

[OverCoat]

find a metronome and tap along

[Yoozer]

120bpm = 1 beat per 0.5 seconds (60 seconds, 120 beats, divide, = 0.5).

140bpm is faster, so the time should be less; and it is; 0.428 seconds per beat.

Use a wave editor. Select 4 beats. See how long they take. Divide by 4. You now have the number of seconds on how long a single beat lasts.

60 / BPM = duration of beat.

If you don't know how to calculate back from that, I give up on today's youth.

[dPaladin]

120bpm = 1 beat per 0.5 seconds (60 seconds, 120 beats, divide, = 0.5).

140bpm is faster, so the time should be less; and it is; 0.428 seconds per beat.

Use a wave editor. Select 4 beats. See how long they take. Divide by 4. You now have the number of seconds on how long a single beat lasts.

60 / BPM = duration of beat.

If you don't know how to calculate back from that, I give up on today's youth.
Alternatively, find the beat in the song, set your stopwatch for 15 seconds, and count the number of beats.

That number x4 is close to the tempo, if not right on it.

EDIT: Your way is better, I'm just providing another example.

[sgx]

I think Acid Xpress is free and it might have the beatmapping feature that the other acid versions have. Might want to check that out.

[sonicbhoc]

If you are lazy, cut out a piece of the song that has a steady beat. Then, use MixMeister's BPM Analyser (http://www.mixmeister.com/download_freestuff.html) and click scan twice to get an accurate reading.

[Reasoner]

Pro Tools can identify a bpm for a selected waveform. Then it can map a grid around it so that it's easy to sequence directly with the recording. Not sure if anyone actually uses protools here though.

[Ghetto Lee Lewis]

You may need to know some music theory and use your own ear/judgement to find a BPM (although for 4 on the floor trance it shouldn't matter a bit).

It can make a big difference knowing the time signature/meter of a song and how beats are divided (i.e. 6/8 time vs. triplets; 4/4, 2/4, 2/2, etc.)

[LegendofSymphony7]

There's some other things that make finding the tempo difficult, too. For one, it's the genre of the music that sometimes sets it apart. From some of what I heard, most techno/trance/lectronica is either in 120 or 140 BPM. All rap is in 120 is it's fast, 60 if it's slow, and 90-107 if it's medium. For rock, metal, or punk you're just gonna have to know the band's average BPM (The average for all music, though, is roughly 120), although punk drummers tend to pull the tempo double-time. (As in 4 on the floor and snare on every *and* when you count 1and2and3and4).

My best advice: Tap your foot every time you hear a bass drum kick followed by a snare. Of course, this probably only works for 4/4 or any meter/time signature with 4 beats (i.e. 6/8 can't be done like this unless 1] you know it's in 6/8 and 2] you're willing to tap your foot in a dotted quarter pattern for two measures. For 3/4, the waltz time signature, you're just gonna have to waltz it).

Oh, and by the way - You just took advice (if you bothered to read this) from a drummer.