What Child Is This with Hark! The Herald Angels Sing arranged for a seven piece brass group, violin, organ, percussion for congregational singing with SATB choir parts. In the Key of F.  3 trumpets, (3^rd trumpet uses flugelhorn), horn, two trombones and Tuba; Violin solo (or flute); Percussion parts for 2 players; piano/organ for unison congregational singing.  There are nice instrumental intros and interludes between some stanza.  Be sure to view the sample score and listen to the audio midi of this arrangement, and view the score/audio on the Youtube link.  Moderately difficult.