How does one go about going "oh, okay, <insert song here> is in 4/4 and then they switch to 3/4 here and then they...." so on and so forth? I know that one measure is "1 2 3 4", and then the measure stars again on every 1, so "One, two three four, One two three four...". where every 1 is the main beat? What is 4/4? Is it 1 2 3 4 four times? If it is, how does, for example, 3/4, or 6/8 etc work? And also as a side question, with all of this in mind, how do you use a metronome to have a basic rhythmic structure?