Tony Bennett, the smooth American singer who had an enduring hit with “I Left My Heart in San Francisco” and remained perpetually cool enough to win over younger generations of fans well into the 21st century, died on Friday, his publicist said.

A statement posted on his Twitter account said: “Tony left us today but he was still singing the other day at his piano and his last song was Because of You, his first number 1 hit.

The artists also collaborated with star performers from Lady Gaga to Aretha Franklin and Frank Sinatra, who called him “the best singer in the business”.

Bennett sold millions of records and won 20 Grammys, including a lifetime achievement award.