Here's a quick tutorial on how to set up the delay time so that your delay FX matches the tempo of the beat.
This can be used on basically anything, like vocals, drums, melodies, percussions. Used properly, this can make things sound richer, or it can spice up a drum pattern, and even help you create a new rhythmic pattern. But to do that, you have to learn how to set up your delay so that it's on time with the tempo of your beat.
Some delay plugins can be set using 1/4 notes, 1/8, 1/16 etc... But others can only be set in milliseconds (ms), so it's important to know how to sync your delay time with your beat.
To find the right delay time, the formula is simple. You start with 60'000 and you divide it by the bpm of your song. This will give you the delay time for a quarter note (1/4).
In this case, the tempo of the beat is 100 bpm, so it's 60'000 divided by 100= 600ms.
For an eighth-note (or a "quaver"), you only have to divide it by 2. 600/2= 300ms
You can also divide 600 by 3, 6 or even 1.5 etc... to get other tempo-related delay times.
For this example, we'll set the delay on 300 ms.
This quick tip can also be used with reverbs, for the pre-delay time, although you're probably going to want a faster pre-delay (probably 1/16 note, or 1/32).
Now, you can always experiment with delays, and try a delay time that doesn't match the tempo of your beat. You can find ways to make it creative and interesting. But in general, you'll want to keep everything in sync with your tempo, and hopefully this quick tip is going to be useful for you!