Determining the Key of A Piece
It is important for you to be able to recognise what key a piece is in, and the way to do this is to identify it from the sharps or flats of the key signature. The key signature, however, does not distinquish between major and relative minor keys; for example, a Signature of F sharp (as in the study above) could indicate either G major or E minor. The two main guidelines for determining whether a piece is in the major or relative minor key are:
- The presence of the 7th note of the minor scale (the leading note). This is the only note of a minor scale (except the "pure" minor) which is not found in its relative major, thus a D# note in the music will strongly suggest the key of E minor rather than G major.
- The name of the finishing note (or chord). A piece very often finishes on its root note and thus an E note at the end would suggest the key of E minor (quite often a piece will also begin on the root note).