For more than 25 years, Rockapella has been spreading the gospel of the power of the human voice sans instruments, from their stint on the beloved PBS quiz show “Where in the World Is Carmen Sandiego?” to sold-out performances and TV appearances. In concert, the New York-spawned a cappella quintet — the current version features vocal percussionist Jeff Thacher, bass George Baldi III, high tenor Scott Leonard, and tenors John K. Brown and Steven Dorian — create a full-bodied sound on original tunes and classic covers.

The group is touring for its forthcoming release, “Motown and More,” stripping back the pop soul hits from that legendary label like the Temptations’ “Ain’t Too Proud to Beg” and “My Girl,” and the Jackson 5’s “Dancing Machine” to their vocal essence. The tour hits the Berklee Performance Center on Friday evening.

We checked in with Leonard, the group’s chief songwriter and lead arranger, about the five best things about performing without instruments. (And where in the world was he when he sent in these answers? Tampa, Fla.)

1. “It’s easy on the back.”

2. “It’s easy to tell who screwed up.”

3. “Working with the same, simple palette for 20 years allows — forces — you to keep approaching it creatively.”

4. “When you do add instruments, such as those of our frequent collaborators, the fantastic Boston Pops, it becomes a mind-bending explosion of glorious sound and wonder.”

5. “It’s cheap.”

Rockapella plays the Berklee Performance Center on Friday at 8 p.m. Tickets: $21-$31. 617-747-2261, www.berklee.edu/bpc