Scarborough Fair is an example of a song in a minor key. Because there is no key signature written at the start of the song, the song is in either C major or A minor. It is usually possible to tell which of two possible keys (major or relative minor) a song is in by looking at the note on which the melody ends, and often the starting note as well.
This melody begins and ends on the note A, so this tells us that the key is A minor. Another indication is the chords which accompany the melody. The first and last chord symbol here is Am which indicates an A minor chord.
Notice the use of the note F sharp (F#) in this song. When sharps or flats occur that are not part of the key signature, they are called accidentals. An accidental is a temporary alteration to the pitch of a note and is canceled by a bar line. Notice also the use of ties.
This version is in the key of C minor, as can be seen from the key signature (3 flats). This key was chosen because it suited our male singer. As mentioned earlier, everybody has a different voice range, so some people will prefer to sing any given song in one key, while others will prefer a different key. The key chosen depends on the range of notes used in that particular melody and whether they feel comfortable for the singer. Often (in a choir, for example) many different singers, both male and female will sing a song in the same key in unison, or in harmony in different octaves. The vocal exercises in this book are sung by male and female voices in the same key, but in different octaves. However, there are times when changing the octave moves the melody too far up or down for an individual’s range. In this situation, finding a new key between the two octaves is usually the solution.