The Japanese In Sen Scale was made popular in jazz by John Coltrane and McCoy Tyner. The In Sen scale is sometimes called the Japanese pentatonic scale and it is found naturally in the major scale and the melodic minor scale. For example the E In Sen scale can be found in C major scale and D melodic minor scale.
The intervals of the Japanese In Sen Scale are:
1 b2 4 5 b7
The E In Sen scale looks like this:
E F A B D
The intervals of the In Sen scale could also be represented like this:
Half step, major third, whole step, minor third.
I love the sound of the Japanese In Scale and find the wide intervals sound it creates to be very melodic. It is kind of like a Phrygian pentatonic scale and is used to play over susb9 chords.
Take the time to get to know the exotic sounds of the Japanese In Sen Pentatonic scale. The In Sen scale is a really melodic addition to your jazz vocabulary. You can learn more about guitar scales by checking out Jamplay which is a great way to learn scales on guitar.