Hello mike I was reading the thread about improvising over change in the chords and thats was the first time i bumped into the "tonal center" thing. I did a search in your forum and read the threads that was connected to this issue, still i would like to get into details with this issue. Can you recommend me a good book that will give me all the knowledge i need in order to make a tonal center analysis even to complexed jazz standards?? (One of yours if you have one that focus on the tonal center and gives a deep view of this issue) It'll Better if you know one that distribute the book in israel because with all this internet orders eventually i'm gonna' end up as a broke bum on the street (sometime those shipping payments cost more then the product itself ) Till i get a good book and will be able to answer it myself i have a question that was on my mind when i read one thread that was including a simple tonal center issue. In this thread you gave an example of the chord progress : G, D, C, G if i remember right you said that this is in G major key because it's i ,iV ,V . Now my question is if i'm improvising a solo on G major scale i can be playing F# (as part of the solo) while the guitar or piano plays the C chord. It would ceate a triton between the root of the chord and my F# and also half tone between the 5th of C chord (G) and the F# , Is it O.k. ?? I'm sure i'm missing something here,what is it??? Thanks in advance Adi.