Legendary singer Liza Minnelli gave a San Francisco audience a pleasant surprise when she joined friend Michael Feinstein for a tune during his recent performance in San Francisco.

The 70 year old screen legend joined Feinstein on stage for a rendition of I Love a Piano. Minnelli’s voice was in fine form and she had a lot of fun with the song.

The Irving Berlin tune was first published in 1910 but it is remembered for its inclusion in the 1948 musical Easter Parade which starred Minnelli’s mother Judy Garland.

Finestein’s show paid tribute to Judy Garland with her other daughter Lorna Luft joining the piano player for several tunes, but nobody in the crowd knew that Liza was waiting in the wings to be part of the show too.