The harmonic major has only one note different to the major scale (Ionian), however, it has a world of different sounds that can completely change how you sound when you comp or solo over a piece. I've take Stella By Starlight here as it encompasses some really common chord movements. As always try as much as possible to take things you learn into other keys...these are some of the things taking things into different keys helps:

 

•Fluidity in all keys i.e. being able to play as effortlessly in Ab Major as in C Major...or in E Major as D# Major. 

 

•Transposing the chords or lines to another key actually helps you learn the original thing faster. It means you need to see all the notes relative to each other in order to transpose to another key (e.g. What is C to G7 in the key of A? Well first we consider C is chord I and G7 chord V. Then think to A and chord I is A and chord V is E.....so in transposing it we think of the original key in numbers, the chords all being relative to each other

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•So my above point in brief; Taking things through different keys really helps you to develop your ear...as well as being prepared for whatever key a singer may throw your way on your next gig!

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