Ringo Starr hit the legendary Viper Room on the Sunset Strip last night to show his support for an up-and-coming British singer ... a singer who happens to be Paul McCartney's only son.

Turns out, 34-year-old James McCartney is already building one hell of a fan base ... 'cause Eagles rocker Joe Walsh also checked out the performance.

Right before the show, we asked James about his favorite Beatles album ... and his answer was pretty surprising, considering it was a record that his dad has said he was unhappy with at the time of its release.

Former Beatles drummer Ringo Starr really is one of the fab four.



Here's the 24-year-old in London back in 1964 (left) -- and 46 years later, the 70-year-old version at a concert in NYC on Wednesday (right).

Let it be.