Diminished Lines are a real earcatcher and will get the attention of your audience, due to it´s sound that will rise up in between all the Pentatonic licks. These lines fit best in bars 11 an 12 (of a 12-bar Blues progression): The following examples are in the key of "A" - Ex.1 shows a possible rhythm of the proceeding 5-4 progression.
Have fun, practising these lines - and don´t use them too much in one or some following songs. Cause they will loose their "magic", when heard too often.
