Good ideas have a way of resurfacing. Such is the case with the Afro Celt Sound System which, after a three-year hiatus from recording, has released their sophomore album, Volume 2: Release.

Still part of the band is the seamless merger between African and Celtic musical traditions. But this album, far from a retread of their previous release, Volume 1: Sound Magic, has a new infusion of pop and techno styles.

Synthesizer-heavy "Hypnotica," for instance, could seque nicely into the mix on any number of nightclub dance floors. And yet the low whistle and harp which dominate parts of the melody don't seem at all out of place there. "Riding the Waves" boasts a frenetic percussion section with jazzy electronic riffs. "I Think Of..." features an alternative-melancholy vocal (in Gaelic), a wild whistle and uilleann pipe reel and a rhythm section straight from the Dark Continent.

The lineup of the Afro Celt Sound System is altered somewhat from the band's previous incarnation. The band now is made up of James McNally on keyboards, whistle, low whistle, bodhran and accordion, Iarla O'Lionaird on vocals, N'Faly Kouyate on vocals, kora and balafon, Myrdhin on Celtic harp, and co-producers Simon Emmerson on guitars, keyboards and programming, and Martin Russell on keyboards, programming and engineering.

If that wasn't enough for a full sound, the album employs a host of guest musicians: Ron Asian on programming beats, Ronan Browne on uilleann pipes, Michael McGoldrick on uilleann pipes and flute, Ashley Maher on vocals, Johnny Kalsi on dhol drums and tablas, Nigel Eaton on hurdy gurdy, and Youth on bass.

Also guesting on Release is singer Sinead O'Connor, whose pop origins haven't overridden her apparent love for traditional Irish singing. Here, she joins the Sound System on the title track, "Release," and her voice seems perfectly suited for the tune -- which blends heavy drums with light harp strokes, whistles and pipes with a frantic hurdy gurdy, and additional vocals by O'Lionaird -- and frankly, I was disappointed she didn't appear again on the album.

The next track, "Lovers of Light," maintains the heavy African and synthesized rhythms, but the spotlight now is on a breakneck duet by guests Browne and McGoldrick on the uilleann pipes. Wow -- I thought I'd be disappointed when I saw that pipe maestro Davy Spillane wasn't back for Volume 2, but this track wiped away my fears.

"Eireann" mingles the voices of O'Lionaird and Kouyate -- the first singing in Gaelic, the second in West African -- and it's an unexpectedly good mix. The delirious beat of "Big Cat" has excellent pipe and flute solos by McGoldrick and an abundance of techno-electric enhancements to keep the sound moving along. Then "Even in My Dreams" slows things down with an appropriately dreamy vocal and melody line -- but even that can't dampen the band's need for upbeat rhythms and harmonies.

The final verdict: Release isn't nearly as startling different as its predecessor, Sound Magic, but at the same time it has more staying power and should gain the Afro Celt Sound System an even broader audience than it had before. Give this one a listen.

[ by Tom Knapp ]