BPM
Beats per minute
Last updated
Beats per minute
Last updated
BPM indicates the tempo of the song e.g. tempo of 60 beats per minute means that there is one beat per second. Although in general the song's tempo can change, Ultrastar requires single tempo for the whole song.
In Ultrastar beat is the smallest unit of time in which notes' positions and lengths are measured. The length of the beat depends on the BPM value. For example for song with:
120 BPM tempo - there are 120 beats per 60 seconds which means that 1 beat lasts half a second (500 ms);
300 BPM tempo - there are 300 beats per 60 seconds which means that 1 beat lasts 200 ms.
Beats are numbered from 0. Usually the first note of the song starts in beat 0. When the first beat begins depends on the value.
Explanation above is simplified. In reality Ultrastar beats are a quarter of the standard beat calculated from the BPM value.
Therefore if you for example specify the tempo as 120 BPM, Ultrastar will calculate its beat duration as if the tempo was 4 * 120 = 480 BPM. One beat will last 500 / 4 ms = 125 ms.
The easiest way is to use dedicated software, e.g. (latest version is paid but you can find older free versions on the web).
The value from BMP analyzers usually needs to be increased for Ultrastar purposes.
Why?
If the song has low BPM value, you will have not enough granurality, e.g. with 15 BPM (Ultrastar will treat it as BPM 60) you can only define note's duration in seconds!
If the song has too high BPM value, you will lose time finetuning notes length, e.g. with 600 BPM (Ultrastar will treat it as 2400 BPM) each beat lasts 25 millisecond, there is no need to be that exact.
If your BPM is too low, multiply it by 2. If it is too high, divide it by 2.
You can create the mapping for the song with any BPM value. However if you choose the wrong tempo, you will have trouble aligning notes' positions.
Let's assume the song's tempo is 300 (so 1 beat lasts 200ms) and we have a note that starts in beat 12 (2400 ms). If you set the BPM to 240 (so 1 beat lasts 250ms) you can only choose between beat 9 (2250 ms) and 10 (2500 ms).
Valid BPM:
must be greater than 0,
can be a real number e.g. 350.67.