Music style endured in "Pitch Perfect" or "Your Friend's College Concert"

• Like some choral performances
• Like some college singing groups
• Lacking backing, in a way
• With no instrumental accompaniment
• Unaccompanied, perhaps
• Unaccompanied singing style
• Without instruments (8)
• Like singing sans instruments

Wikipedia Word definitions in Wikipedia
Returning to their roots, Johnny Maestro and The Brooklyn Bridge released Acappella , a collection of notable doo wop covers.