"Chorales" are works where material is presented primarily (or solely) using chords.
They use typical chords and riffs but in thoroughly unfettered ways.
He plugged the numbers into the music's harmonic material, using fifth chords.
Other Stations use successive chromatic chords and may abruptly end on a single tone.
Example (b) shows the same effect using fourth chords instead of triads.
Palm was also often progressive, in the sense of not being afraid of using chords that were relatively unusual for his time.
However many of the pieces include large sections where they have to improvise (make something up) using particular chords.
Recent musicians change make more harmonic changes than in the past, but still use only major chords.
He uses interesting chords just for the sound that they make.
He liked to use unusual chords just for their own sake, not in order to make them lead to a particular key.