Hi, Neo,

How do you know that a drummer knocks at the door?
The knocking grows faster and faster.
That is why I use a metronome in practising. I have an electronic device with sound and light signals, and since the snare isn't a piano instrument, I use earplugs.
The metronome was invented by the German Maelzel to record Beethoven's tempi exactly, not only by such words like "adagio" or "presto". Beethoven was so enthusiastic with this invention that he wrote a funny catch: "Ratatatatta ratatta ratatta-a, (lieber) dear, lieber Maelzel ..." imitating the ticking of the metronome in the first lines. Sounds wonderful, we sang it at school.

Wilfried