Step 5: Take Song Notes
It's time to take some notes! Open up Notepad, and bring up Winamp again (GoldWave works just fine, too, but shareware can be annoying, so you might as well use Winamp instead). Remember to change Winamp's output plugin back to the default "Winamp waveOut" selection as shown below.
Now, listen to your song in detail. The point of this is to count how many measures your song consists of, counting only the portion within the selection you noted earlier. Most DWI songs are comprised of 4 beats per measure (aka 4/4 time), but yours may differ, so make sure you account for this before and during note-taking.
I like to type the number of measures a section is comprised of, and then name each section. I usually name it after its key instrument, or the first few words of the lyrics in that section, since it helps me get an idea of the way the song is laid out.
As you can see in the sample picture, songs tend to have sections that are 8 measures long, with the same number of beats per measure. However, exceptions frequently pop up, so make SURE you account for any divergences from the norm. If necessary, tap your finger to keep track of the beat while you count the measure in your head. This may take a replay or two to get right.
Once you've finished mapping out the song, add up the total number of measures in all the sections you noted. Then, multiply it by the number of beats per measure. Once again, make sure you take any irregularities into account. Your result should be the total number of beats in the entire selection.
Now, for some math. Divide the number of beats in the selection by the number of seconds in the selection.
My song - Key of the Twilight - turned out to have 416 beats within a period of 207.971 seconds. Dividing beats by seconds, that equalled roughly 2.000278 beats for every 1 second that passed in the song. Anything less than .001 second is not terribly important, so I rounded this off to an even 2 beats/second.
Now, to convert that to BPM (Beats per Minute). Simply multiply it by 60, as there are sixty seconds in a minute:
We have a tempo! Now, we need a DWI file to enter it into for testing, to make sure no mistakes were made in the process of calculation.