Bardic Voices: The Robin & the Kestrel by Mercedes Lackey
Paperback. Condition: Very Good-. 1993. Baen Books.
Book #2 in the Bardic Voices series.
While traveling the open road together, Robin, a gypsy bard, and Kestrel, heir to a throne he does not want, try to tame a killer ghost and also foil a plot to drive all music from the land.