Progressions in D# — Cello

D# major harmonises to D# – Fm – Gm – G# – A# – Cm – D°; D# minor to D#m – F° – F# – G#m – A#m – B – C#. Each chord links to its tone map on the Cello, so a tune in D# becomes a short list of places the hand needs to be.

The useful question in a key is which open strings it agrees with. In D#, check the chords against the open C and A — a key that leaves an open string ringing under the melody is a key this instrument was built for.