Rihanna showed up to perform with Paul McCartney at 'Oldchella', no big deal

During the second week of the Desert Trip music festival in Indio, Calif., Rihanna took the stage alongside Paul McCartney in a surprise appearance, but it's uncertain if some audience members knew who she was or even cared.

The 28-year-old performed FourFiveSecondswith the former Beatles member, who later made a joke to the crowd that they finally found someone under the age of 50.

Desert Trip's performers this weekend and lasthave included enduring artists such asBob Dylan,the Rolling Stones and Neil Youngamong others. Their average age is72. The average age of the audience is estimated at 51, according to reports.

While there were social media messages aboutRihanna'ssurprise appearance, including one from McCartney on Instagram,there was hardly the kind of feverish postingshe'd get from her typically younger audience.

The official Desert Trip Twitter andFacebookpages didn'tpost about it either, and the seemingly ambivalent reception from the crowdwhen she appearedshows much of the audience mighthave been just as happy withMcCartneyalone.

The festival took over the Empire Polo Clubgrounds inIndio, Calif., much like the popular annual music extravaganza,Coachella. Desert Tripwas unofficially dubbed "Oldchella" because it obviously catered to ababy boomer demographic.