Hey Jazzsurfer. This is a common thing you will see in many jazz standards
Using the #iv as a minor b5 or diminished chord to start a "walk down". It also functions nicely as a tritone sub for the minor iv chord that follows. I know it's not a "standard" dominant to dominant tritone sub, but it still functions very similarly. C#7 to Cmaj works well, but C#7 to Cminor doesn't work as well due to the voice leading. So many guys will sub it out for C#min7B5 to Cmin7 when using this sound. Or even C#min7 to Cmin7 depending on the situation and key you are in.
C# E G B to C Eb G Bb
Your root, 3rd and 7th drop a 1/2 step and it provides a strong voice leading sound. The chord itself also has a "tension" to it based off of the key we are in so it's a great ear catching sound to start the walk down!
A lot of players will also play Bmin7 instead of Gmaj7/B when they get there. That effectively leaves the line as
C#min7b5 Cmin7 F7 Bmin7 Bbmin7 Eb7 Amin7 D7 | Gmaj6
If you do this, the Bmin7 functions the same way as the C#min7b5 !!! The reason one has the b5 is due to the melody and the key center we are in.
Enjoy!!!
*** A side thought as you go through your analysis of things. Instead of marking everything how it relates to the tonic, why not just delineate ii V's and if it is a ii V of another key, you note that with parenthesis ? Because that's exactly how a bop player or "jazzer" would be treating these. Everything is a ii V or rather V to I. This way when you practice vocabulary you can just take your ii V vocabulary around the keys and you'd be good to play on this tune by sequencing it through all the ii Vs!!!
If I have time, I'll make an analysis how I see it and post it later so you can see what I mean.
Using the #iv as a minor b5 or diminished chord to start a "walk down". It also functions nicely as a tritone sub for the minor iv chord that follows. I know it's not a "standard" dominant to dominant tritone sub, but it still functions very similarly. C#7 to Cmaj works well, but C#7 to Cminor doesn't work as well due to the voice leading. So many guys will sub it out for C#min7B5 to Cmin7 when using this sound. Or even C#min7 to Cmin7 depending on the situation and key you are in.C# E G B to C Eb G Bb
Your root, 3rd and 7th drop a 1/2 step and it provides a strong voice leading sound. The chord itself also has a "tension" to it based off of the key we are in so it's a great ear catching sound to start the walk down!
A lot of players will also play Bmin7 instead of Gmaj7/B when they get there. That effectively leaves the line as
C#min7b5 Cmin7 F7 Bmin7 Bbmin7 Eb7 Amin7 D7 | Gmaj6
If you do this, the Bmin7 functions the same way as the C#min7b5 !!! The reason one has the b5 is due to the melody and the key center we are in.
Enjoy!!!
*** A side thought as you go through your analysis of things. Instead of marking everything how it relates to the tonic, why not just delineate ii V's and if it is a ii V of another key, you note that with parenthesis ? Because that's exactly how a bop player or "jazzer" would be treating these. Everything is a ii V or rather V to I. This way when you practice vocabulary you can just take your ii V vocabulary around the keys and you'd be good to play on this tune by sequencing it through all the ii Vs!!!
If I have time, I'll make an analysis how I see it and post it later so you can see what I mean.
