Lunation, by composer Chad Heiny, is a two-movement duet for vibraphone and marimba. Inspired by the changing from one new moon to the next, it symbolizes lessons learned (I. Old Moon), and new beginnings (II. New Moon). And much like the life symbolized within the music, there is no pause between movements. The music is perfectly representative in the reflectiveness of the old moon, and the buoyant, hopeful jubilation of the new. The latter will surely challenge players with a nearly constant array of flourishing runs and tightly woven interplay. The result is a joyful and satisfying journey for performers and listeners. Lunation ships as a printed, professionally bound score, and includes individual parts in PDF format for printing or tablet viewing.