Link to piece on musescore = https://musescore.com/user/92750977/scores/22672477?share=copy_link

Attempt at producing a 16-bar piece of music using the Lydian mode. I opted to use Piano for the harmony and Cello for the melody.

I chose A major and then raised the 4th scale degree, D to make it D#. Other than one accidental Bb in the 4th bar I stuck within this key throughout. I might be wrong about this, I think the D# from the mode makes the ii chord in the diatonic chord progression a Major II chord rather than a minor, and the vii diminished chord becomes a vii minor chord as the 5th is raised a semitone.

As a result, I think the chord progression is:

I - II - V - iii II -

I - II - V - iii II -

I - II - V - iii II -

I - II - V - iii II -

I - II - V - vii - V - I