I guess you are talking about the header and the footer. The upper is called header, and the lower is called the footer.
two
Yes, you can change your signature at any time. It is not a permanent and unchangeable part of your identity.
The bottom number indicates what duration of note gets the beat.
The bottom number indicates what note value gets one beat.
The time signature is the time and beat of the song, and the key signature is what major or minor it is in
2/2 time signature
its time signature is 3/4
The time signature is placed on the staff between the clef and the key signature.
MESSAGE date/time content signature (name)
It comes before the time signature. The clef comes before the key signature.
It means there are two notes to the bar, of the size indicated by the lower number.
What is the time signature of dance?