Instrumental Duet Instrumental Duet,Piano - Level 3 - Digital Download SKU: A0.798362 Composed by Paul Hemmer. Halloween. Score and parts. 15 pages. PJMS MUSIC #6499257. Published by PJMS MUSIC (A0.798362). Ghosts on the Loose for two pianos is a Halloween novelty that is fun to perform and will delight audiences. It is loaded with good musical humor and challenges the performers with abrupt dynamics.