Instrumental Duet,Piano Instrumental Duet,Piano,Viola,Violin - Level 2 - Digital Download SKU: A0.1212958 Composed by William Runyan. Arranged by Tyler Adams. Christian,Praise & Worship,Religious,Sacred,Traditional. 13 pages. Adams Arrangements #810155. Published by Adams Arrangements (A0.1212958). Great Is Thy Faithfulness warmly arranged as a duet for violin and viola with piano accompaniment.