About a half-hour into Santana's show at Merriweather Post Pavilion last night, the San Francisco octet launched into its version of the Zombies' "She's Not There" with an overdone, soulless vocal by Alex Ligertwood. This in turn led to Carlos Santana's very long guitar solo, which showed flashes of brilliance but also meandered aimlessly. The energy level of the show immediately doubled, however, as New Orleans' Neville Brothers Band joined Santana on stage. The 15 assembled musicians created an intoxicating polyrhythmic drive behind Aaron Neville's gorgeous soul vocal on Jerry Butler's "For Your Precious Love" and behind Art Neville's gutsy rock vocal on Santana's "Freedom." Suddenly Santana's music had a focus it had lacked.

Santana'snew album, "Freedom," is its best effort in years because Ligertwood was replaced as vocalist by Buddy Miles. Unfortunately, Ligertwood has replaced Miles in the touring band. When Santana steered clear of vocals, which was quite often, the performance was frequently exhilarating. All four percussionists were virtuosos, and former Weather Report bassist Alfonso Johnson and one-time Tower of Power keyboardist Chester Thompson added authentic jazz touches. For all the skill of the band and its leader, though, the show sacrificed drama for whims.

In the opening set, the Neville Brothers Band made a surprising break with its past and declined to sing such old favorites as "Tell It Like It Is" or "Hey Pocky Way." Instead it focused on songs from its new album and even newer unrecorded material. Aaron Neville's tour de force vocal on "Drift Away" won a well-deserved ovation from the skeptical Santana fans; just as impressive were the frenzied calypso carnival rhythms of Cyril Neville's tribute to Nelson Mandela, "That's My Brother."