Minor scales are sometimes said to have a more interesting, possibly sadder sound than plain major scales.
Like major scales, minors are named after their tonic (first) note. However unlike majors, minor scales do not have their own set of key signatures. Instead it is necessary to use the key signature of a minor's relative major scale. The relative major is found augmenting the minor tonic note by 3 semitones; for example the relative major of E minor is G major. We know that the key signature of G major is two sharps (see major scales for how to find this,) therefore E minor also has two sharps in its key signature.
This table illustrates the relative major key signatures for minor scales.
Key Sig. Major Scale Minor Scale 0# - C major - A minor 1# - G major - E minor 2# - D major - D minor 3# - A major - F# minor 4# - E major - C# minor 5# - B major - G# minor 6# - F# major - D# minor 1b - F major - D minor 2b - Bb major - G minor 3b - Eb major - C minor 4b - Ab major - F minor 5b - Db major - Bb minor 6b - Gb major - Eb minor
Scales produced from just using the key signature of the relative major are called natural minors. There are two more common types of minor scale: melodic melodic scales and harmonic minor scales. The melodic minors are constructed by sharpening the 6th and 7th degrees of the ascending scale, but not sharpening these notes on the descending scale.
Harmonic minors are constructed by sharpening the 7th degree of the scale both ascending and descending.