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 FourFiveSeconds with 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 last have included enduring artists such as Bob Dylan, the Rolling Stones and Neil Young among others. Their average age is 72. The average age of the audience is estimated at 51, according to reports.

While there were social media messages about Rihanna's surprise appearance, including one from McCartney on Instagram, there was hardly the kind of feverish posting she'd get from her typically younger audience.

The official Desert Trip Twitter and Facebook pages didn't post about it either, and the seemingly ambivalent reception from the crowd when she appeared shows much of the audience might have been just as happy with McCartney alone.

The festival took over the Empire Polo Club grounds in Indio, Calif., much like the popular annual music extravaganza, Coachella. Desert Trip was unofficially dubbed "Oldchella" because it obviously catered to a baby boomer demographic.