Arpeggios
Dm7 arpeggio = D F A C
Emin7b5 arpeggio = E G Bb D
A7 arpeggio = A C# E G
Scales
D Minor Scale: D E F G A Bb C (D) - works on Dm9 and Em7b5 chords
D Harmonic Minor Scale: D E F G A Bb C# (D) - works on A7 chords
Next level for the dominant (A7) chord
A Super Locrian: A Bb C Db Eb F G (A)
This is the 7th mode of Bb Melodic Minor...