Eight years after Tonic faded into the sunset as lead singer Emerson Hart took a flier on a solo career, the band has reunited and belatedly released their fourth album, and the set, simply titled Tonic, sounds like the work of a band picking up right where they left off in 2002. Tonic’s hard rock influences seem to have been dialed back a notch or two, but Jeff Russo’s lead guitar still brings forth an arena-ready crunch on “Bigger Than Both,” “I Want It to Be,” and “Torn to Pieces,” and the melodies still reach for a Grand Emotional Gesture as they lock in on a radio-ready hook (or at least what was a radio-ready hook in the late ’90s). Even though they’re recording for an indie label these days and original drummer Kevin Shepard has been replaced by Pete Maloney, Tonic seem to have been changed remarkably little by the passage of time, which given the circumstances, is a braver move than it might seem — radio is far less likely to embrace this sort of archetypically post-grunge music than they were in 1996 when “If You Could Only See” topped the charts, and while loyal fans will doubtless be pleased with this album, it’s anyone’s guess how many are still out there given Tonic’s eight-year intermission. Thankfully, Tonic doesn’t sound like the work of a band struggling to re-create their past success, and instead finds them confidently embracing their signature sound and doing what they do with a sure hand and genuine inspiration. Emerson’s vocals are as effective as ever, the songs (written by Hart, Russo, and bassist Dan Lavery) capably play to the group’s strengths, and Nathaniel Kunkel’s production gracefully fuses the melodic and electric sides of their music. Tonic is less a comeback than an enthusiastic return to form, and anyone who enjoyed their first three albums will feel comfortably at home with this music. – Mark Deming