Paul McCartney has been dusting off rarely performed Beatles songs for the past few months, and the 71-year-old stuck to his nostalgic streak during Outside Lands this past weekend. Macca peppered his nearly three-hour set, which ranked as one of the 10 Best Things SPIN Saw on Friday, with previously little-heard tunes such as “Lovely Rita” and “Being for the Benefit of Mr. Kite!,” but the Fab Four survivor pulled out another unexpected show-stopper: He played 1965’s immortal “Yesterday” with a live string accompaniment provided by the iconic Kronos Quartet. Despite being known for sometimes crafting, ahem, liberal reinterpretations of rock classics (see Jimi Hendrix’s “Purple Haze”), the San Francisco foursome offered a straightforward rendition of the Help! highlight, allowing for a festival-sized sing-along led by McCartney. Watch it above, and scroll down for SPIN’s extensive Outside Lands coverage.