Euphonium Solo - Level 4 - Digital Download SKU: A0.1257939 By Jake Rogus. By Jake Rogus. 21st Century,Contemporary. Individual part. 1 pages. Jake Rogus #851175. Published by Jake Rogus (A0.1257939). A solo piece for euphonium without accompaniment. As the name suggests, triple has everything to do with threes; the time signature, the intervals, and other aspects of the piece. Tonally, the euphonium travels to a lot of different places but has an e-minor core.