If you are wanting to play your synth instrument “in time”, you may want to activate a metronome to hear a clicking sound that will let you hear the passing of each “beat”.

A metronome is a device that helps musicians keep “time” by clicking at a specified Beats per Minutes or BPM.

So for example, at 60 BPM, the metronome would click once per second, or 60 times per minute. At 120 BPM the metronome would play 2 clicks per second or 120 clicks per minutes. Likewise, at 30 BPM the metronome would click once every 2 seconds, or 30 times per minutes.

Obviously, not all music is locked to some multiple of a second. So, you may set the metronome to 52 BPM or 138 BPM. In these instances you would hear a click every 1.153 seconds or 0.434 seconds, respectively.

To turn on the metronome in Reaper, you need to select the metronome button, which is shaped like a traditional, pendulum-based metronome.

If you select this, then hit play, you should now hear a metronome click.

You can specify the BPM that the metronome and session should be set to, within the Transport section. Simply type in the BPM you desire.

Metronomes are useful depending on the type of music or sonic art you are creating. This is one of the tools that you may use a lot, or never. It will depend on the artistic practices you are interested in pursuing.