Mr. Big were one of the last hair metal outfits to score a hit before January 1992, when Nirvana’s Nevermind topped the charts and ushered in the grunge revolution. With America starting to shift its focus away from ‘80s music, Mr. Big turned their focus to countries like Japan, where audiences remained sympathetic to the band’s supersized hard rock until their breakup in 2002. Released eight years later, What If... marks the return of Mr. Big’s original lineup, with guitarist Paul Gilbert (who originally left in 1997) joining his bandmates for a back-to-basics collection of muscled rock songs and over-proficient instrumentation. Of course, 2010 isn’t exactly the right time for a Mr. Big album -- it’s nearly two decades too late -- but What If... has something working for it that none of the earlier Mr. Big albums had: nostalgia. Those who miss the hairsprayed days of guitar virtuosos and Reagan/Bush-era machismo are in luck, since this is a product of an earlier time, with few signs of the 21st century apart from vocalist Eric Martin’s diminishing range and his bandmates’ shorn heads. Gilbert still fingertaps his way through more than a dozen solos, Billy Sheehan still plays the bass like a guitar, and the full band still sings harmony, an asset that helped Mr. Big differentiate themselves from other hair metal groups during the genre’s heyday. The album’s biggest asset, however, is nostalgia, and those who are willing to forgive the somewhat outdated approach of What If... will get the most out of this reunion record.