The result was an exceptionally heavy album filled with crunchy riffs, modernized by removing the trademark keyboards and guitar solos from Petra's sound. In an Inpop-produced statement, Schlitt called the album "our most aggressive rock record so far." Critics and fans alike greeted the album with acclamation, hailing it as the band's "best album in years" and "one of this year's biggest musical surprises," "a powerful rock effort ... bordering on metal." For the first time since "Petra Praise 2", six years earlier, the band broke onto the Billboard charts, peaking at No. 22 on the Christian albums chart. The album also garnered Petra its 13th Grammy nomination. With no keyboardist necessary on tour, a first for the band since its earliest days, and Hartman returning to the stage, the band needed only to replace Weaver, hiring Paul Simmons shortly after the album's release. Petra then prepared a worldwide tour beginning in 2004, including a June show in Indiana that featured a reunion of original members Hartman, Hough and DeGroff in the middle of the contemporary band's set. Simmons filled in for original drummer Glover, who was invited but could not attend. Shows in India near the end of the year featured crowds as large as 20,000. Despite rumors that Petra was working on another studio album, John Schlitt announced in May 2005 that he and Hartman had agreed to disband Petra at the end of the year, following a short farewell tour. As a final sendoff, Petra recorded its show in Franklin, Tenn., on Oct 4, which included special appearances by Volz and Lawry, each performing on a handful of songs from his tenure with the band. The performance was released on CD in November and DVD in March 2006, each titled simply "Farewell". Petra's last performance began December 31, 2005, in Murphy N.C., and ended shortly after midnight, January 1, 2006, nearly 34 years after Hartman founded the band. Schlitt and Hartman, after arranging worship music together for a youth retreat, reunited for an independently released praise-and-worship CD in 2007, calling themselves II Guys from Petra and titling their album "Vertical Expressions". The songs featured contemporary praise songs in a raw-sounding, electric rock format, and included two bonus tracks from Petra's recorded farewell performance that had not been included on the "Farewell" CD. Studio musicians played drums and bass, and former Petra keyboardist Jim Cooper teamed with Hartman on production.