how do you tell what key a song is in?

Answer 1

In sheet music, there are the key signs next to the clef. If you don't have one, you can know it from the chords combination. If you don't know the chords, you can know it from the notes of the song.

If you don't know the notes of the song, learn music!

Answer 2

If you have the sheet music, it is really quite easy. In a flat key, you count down one fourth, or four notes, from the last flat. Even easier, if there is more than one flat, go to the next to last flat (from right to left). That is the name of the key. For example, with only one flat (Bb) count down four notes and you will end up on F. (You start on Bb). That is the key. The key of F has one flat, a Bb. After that, with 2 flats, they are Bb and Eb. The next to last flat is Bb so now you are in the key of Bb. This continues through the order of flats. They are: B, E, A, D, G, C, and F, in that order. If the last flat in your key signature is G, you are in the key of Db.
If there aren't any flats or sharps, you are in C.
Sharps are just as easy. The order is the reverse of the flats (F, C, G, D, A, E, and B). Go to the farthest sharp on the right and go up one step. That is the name of the key. For example, if the last shard is D, you are in E.
Remember, if there is a flat or sharp on the line or space that is the key name, it becomes part of the key name.
These are just major keys. To check and see if you are in a major key, after figuring it out, look at the first and last note of the piece. One or both will most likely be the same as the key, probably the last note. Hope this helps.

Answer 3

i don't know but i searched for "how to tell what key a song is in"
there you go :-P

Answer 4

If you have the sheet music, it's indicated right next to the clef.

Answer 5

you could just get a music tuner to find out or you have to have an ear for music.