theres a chord progression that goes Bbmaj7, Dmin7, Fmag7 and Ebmaj7 (all lasting for a bar each) with a bass line underneath going Bb, A, Ab, G (all lasting for a bar too). could someone please tell me whats going on with the key and why the bassline fits so well?

Hello Sean, 

Try this: Key of Bb: IMaj7, dm7- iii in second inversion, fm7 is vm7 with Ab in the bass (you cannot use FMaj7 over Ab), EbMaj7 over g is IV7 in first inversion in continuing it could go iv7 in first inversion Ebm7 over Gb then I64 Bb over F is Bb in second inversion. By now you have set up the key of Bb so you could go on Bb or go elsewhere. With figured bass you would have Bb: I7, iii64, v65, IV65, iv65, I64. 

This gives you a chromatic bass line from the tonic Bb to the dominant F. This excerpt fits mostly in Bb with some chromatic passing chords. 

If you are writing this out be sure to consider the voice leading for best results. 

MusicGoals Eye and Ear provides activities to master Roman numeral analysis and figured bass. This study begins with the study of scale-tone chords.

Can you explain linear diminished seventh chords?

Krislynn

Hello Krislynn,

The term linear suggests a melodic line. The notes of a chord may be sounded together at once or one after another in a melodic line.

The diminished seventh chord consists of Root, minor 3rd, diminished 5th, and diminished 7th, for example C - Eb - Gb - Bbb(A).

For more on chords:

http://www.musicgoals.com/WebHelp/MGHelp.htm#Chord_Construction.htm

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