Possible Clues:

• I, too, roar at musical composition with Biblical theme
• Sacred musical composition
• The speaker gets ten more if it's to be sung (8)
• Nought but one pest or ten more to be invoiced
• Handel's ''Messiah,'' e.g.
• 'Ornblower drowns leading members of orchestra in The Creation, perhaps
• Handel's 'Samson' or 'Saul'
• Sounds wholly holy or at or ten
• Bach piece
• Musical composition usually with biblical theme (8)