For both lever and pedal harp:
Passage. Advanced difficulty. Includes versions for lever and pedal harp. Note that there is a short section that is omitted in the lever harp version, and you will need to tune your B strings to B natural with your levers down.
Fantasy on Greensleeves. Intermediate AND advanced difficulty. Includes 3 version – an advanced pedal harp version, an intermediate version for pedal harp, and an intermediate version for lever harp.
Uncharted Shores. Advanced difficulty. Includes versions for lever and pedal harp. Definitely easier on lever harp, since you set your levers at the start of the piece and there are no lever changes during the piece. The pedal harp version, on the other hand, requires quite a few pedal changes.
For the Earth: Song without Words. Intermediate difficulty. Includes versions for lever and pedal harp.
Nordic Spaces. Intermediate difficulty.
For pedal harp only:
Poem for solo harp. Advanced difficulty.
For lever harp:
Five Solos for Lever Harp. This book contains my compositions Forgotten Summer. It’s very playable on pedal harp as well, but 3 of the pieces from the book are really only useful for lever harp (the Elgar, Bach, and Beethoven).