Hi Dario. I think you should discuss this with fellow musicians – it is a more complex topic than you believe.
For example, a quarter note at 120 bpm in 4/4 time is 500 mS, so at 100 bpm it would be (120/100)*500 = 600 mS. But, if the time signature was not 4/4, it would be different again.
You will see the problem.
