String Trio Cello,Viola,Violin - Level 2 - Digital Download SKU: A0.1321581 Composed by Miriam Troxler. Chamber,Children,Instructional. 2 pages. Miriam Troxler #910054. Published by Miriam Troxler (A0.1321581). A D minor round in 4/4 time, Hot Cocoa is a smooth, sonic experience. It is a great piece to practice vibrato and tone. The cello and the viola parts double for smaller ensembles. An optional piano part is included for rehearsal convenience.