What a difference eight months has made for the Goo Goo Dolls.

Eight months, some time off, a strong new upcoming album and the start of a new tour, that is.

After a solid but hardly soaring show at Bethlehem's Musikfest festival in August, The Goos returned to Bethlehem on Sunday for a show at Sands Event Center that found the band stronger and sharper than they've appeared in years, seemingly energized and invested -- especially in the new music, which also is the band's best in years.

In an 85-minute show, the Goos played 21 songs -- including five from the new album "Magnetic," due out June 11 that offer some fresh new direction for the band, which in the past decade has been stuck offering similar -- but still good -- soaring power ballads. It also offered some inspired deeper cuts.

But what helped make the show so good was that the band infused the many favorites it played with a stronger rock vibe, making its sound urgent and vital again.

On just the third date of its new tour, the band opened with "Long Way Down" from its 1995 breakthrough album "A Boy Named Goo," perhaps a symbolic blast to let the smallish audience of perhaps 2,000 know the band, its members now in their later 40s, still is capable of rocking. And at the end of the song, bassist Robby Takac raised a triumphant fist.

The band followed that with a run of five of the dozen hits it played on the night, an energetic and harder-rock version of "Slide," with front-man John Rzeznik changing up the phrasing. "Naked" was especially good and one of the night's best -- sharp and forceful, Rzeznik singing with emphasis and playing lead guitar, something he's been leaving more to the band's two backing players in recent years.

In fact, Rzeznik played leads several times, to good effect, during the show.

"Cuz You're Gone" was burning, booming rock, and even had a bluesy (!) middle. "Let Love In" was stronger and more muscular, and even the largely acoustic "Name" -- the first strums of Rzeznik's guitar drew cheers -- was stronger. If it lost any of its subtlety, it gained in energy and force.  

It wasn't only that the band was more rocking that made it better. "Here is Gone" had Rzeznik singing in a lower register, but it worked -- making it more a song of resolution than pleading. "Black Balloon," on which Rzeznike demonstrated his voice can still soar, was nonetheless more resolved and resolute. Even "Better Days" was better sung.

A pleasant surprise were the four songs Takac sang. The early pairing of the excellent "Now I Hear," an  underappreciated song from 2010's "Something for the Rest of Us," and the older nugget "Tucked Away," a blast on which Takac cut loose, were great, sounding fresh and Takac singing his, heart out.

A later pairing with Takac on vocals were two full-bore-rock offerings: "Another Time Around," with Rzeznik playing good lead guitar, and the new "Bringing on the Light," which was a throwback to the band's earliest, more punk days.

While that song was good, it wasn't the best of the new songs. That was "Come to Me," an acoustic folk/Americana song that had great layered vocals. Rzeznik was particularly invested, and good on guitar, as well. The song was a definite departure from recent Goos singles, and all the better for it.

The new album's first single, "Rebel Beat," also was very good, another break from the power ballads with its retro-rocky vibe and chanty chorus. And Rzeznik again seemed determined on it.

The two other new songs, "When the World Breaks Your Heart" and "Keep the Car Running," both were more like recent Goo Goo soaring ballads, but also good.

The band closed the main set with a strong "Stay With You," Takac stalking the stage, and a good "Broadway," which Rzeznik started a cappella.

It returned for an encore of its 2005 No. 1 cover of Supertramp's "Give a Little Bit," more rock and stronger -- even with added sax -- and, of course, "Iris," its biggest hit.

But even that song, now 15 years old and an overplayed platinum hit, found Rzeznik singing with his most emphatic voice of the night, seemingly entranced at the end, repeating its chorus, "I just want you to know who I am."

That song was the highlight when the Goo Goo Dolls played Musikfest because they brought on stage with them George Dennehy, the teen who was born armless and became an Internet sensation for playing Goo Goo Dolls songs on the guitar with his feet.

On Sunday, the song was similarly strong, but the Goo Goo Dolls did it alone.

What a difference eight months has made.