Paul McCartney Does Virtual Duet with John Lennon During WA Concert

Paul McCartney and John Lennon's relationship is often seen as bitter, but this week ... Macca seems to have made it clear ... him and John can still come together, even now.

The Beatles frontman was performing this week in Spokane, WA ... and toward the end of the show, during an encore performance, PMC started strumming to his band's song "I've Got a Feeling" -- which appears on The Beatles' last album, "Let It Be."

The song is also featured in their new 'Get Back' documentary ... featured as one of the songs Paul and co. performed on the rooftop of Apple Corps HQ in London.

Of course, he was also side by side with his then-bandmates -- including the late Lennon -- which is what this moment all the more cool ... Paul beamed in JL's video performance of the song live and worked it into the set.

As soon as John's face appeared on the screen behind Paul, the audience went crazy ... and it seems his vocals were coming through quite nicely through the sound system in the building.

Paul weaved in and out of John's singing seamlessly with his own, and at one point ... they were in a full-blown duet together, just like old times. Before John faded out, it appears Paul even turned to face the screen to give a thank you wave.

It was seriously awesome, and kinda puts to bed the idea that there's any bad blood between the pair -- despite the fact Paul recently cast blame on John for breaking up the band.