Steve Martin left flabbergasted!

Steve Martin says it was an honor to have Paul McCartney perform on his latest bluegrass album Rare Bird Alert.

The Hollywood actor-turned musician says he’s  surprised to have collaborated with one of his childhood idols on the track Best Love.

“It’s very hard to believe,” Martin said.”I was a kid when I first heard Paul McCartney, and if you told me one day that he’d be singing one of my tunes… I’m still flabbergasted.”

Martin hit the top spot of the US bluegrass charts with his debut albumThe Crow: New Songs for the 5-String Banjo in 2009.

Rare Bird Alert which also features Dixie Chicks and The Steep Canyon Rangers was released on March 15.

Martin recently revealed he fell in love with Hollywood after making his first movie.

“Once I started doing it (making movies), it was the only thing I wanted to do,” he said.

“I have a movie coming out this year.

“I hadn’t done a movie in a while. I walked onto the movie set and I thought, ‘Gee, I really like this.’ It felt like home.”