A major retrospective of work by Ono opens at the Japan Society in Manhattan, New York, next week, while Sir Paul is to show work in his home city for the first time.

Sir Paul McCartney: His first UK exhibition is in Bristol

Sixty paintings will go on display at the Walker Art Gallery, Liverpool, where the song writer and his friend John Lennon spent "many a pleasant afternoon".

Ono's show opens in New York before travelling to Minneapolis, Houston, Cambridge, Massachusetts, Toronto, San Francisco and Miami.

The exhibit covers works from 1960 to the present, although it focuses on the '60s and '70s.

In a recent interview Ono said: "I always felt that my work is very closely connected with my life.

"And in my life I always felt that I was an outsider, and so that I kind of built up this energy of being an outsider ... and that probably is one of the reasons that people do not want to remember me."

The work is broadly avant-garde and installation-based. Although some of it is more than 20 years old, it would not look out of place in any of the modern art shows which have inflamed critical and public opinion in recent years.

Ceiling Painting: Typical of the challenging work by Yoko Ono

In one piece, Ceiling Painting, a magnifying glass hangs from a chain above a white step ladder. Affixed to the ceiling is a framed piece of paper with the word YES written in tiny letters.

In contrast, Sir Paul's work is more traditional, if abstract, painting.

Sir Paul's show was announced during a live Internet webcast on the Yahoo! chat site with the former Beatle.

I didn't tell anybody I painted for 15 years but now I'm out of the closet

Sir Paul McCartney

He said: "I've been offered an exhibition of my paintings at the Walker Art Gallery in Liverpool where John and I used to spend many a pleasant afternoon. So I am really excited about it."

The show will open in October next year and run until January 2002.

"I didn't tell anybody I painted for 15 years but now I'm out of the closet," he added.

The exhibition will be drawn from a prolific body of work created by Sir Paul over the last 12 years.

The first UK exhibition of Sir Paul McCartney's art work is open in Bristol at the moment, with more than 500 paintings on display.