As you may know, bpm is a way to measure clock speed. Clock is a requirement for any type of sequencing (mapping note events to the time)
Metro class is designed for such purpose. In a nutshell, metro is an oscillator with period of 2pi. Every 2pi metro will return a trigger. It’s up to you which frequency to use. Hz is defined as one cycle per second, so with 1Hz you’ll get 1 trigger per second, or 60bpm.
I am using metro class in my project for sequencer/track playback. But I use much higher resolution, to be able to capture resolutions such as 1/8, 1/16, 1/32 etc.