"Hello Dolly!" was also a #1 hit for the great Louis Armstrong in 1963, when he was in his 60s. It was Armstrong's biggest hit ever, so big it even knocked The Beatles out of the #1 spot for a few weeks. Armstrong changed the words a bit, singing "Hello Dolly, this is Louis, Dolly", using his preferred pronouciation of his name, with a sibilant "s": "Lewis", not "Louie".
Arvell Shaw, who played bass with "Pops" for decades, relates a funny story in Ken Burns' documentary, Jazz. The band went into the studio to cut a record and they were presented with the music for "Hello Dolly!", amongst other songs. Louis protested, "What is this shit? I gotta play this?" to which Arvell replied, "Come on Louis, just do it." And so the song was committed to tape.
The band, on tour in Europe, were unaware that the song had become an instant hit, and so, when the audience began calling for the song at concerts Armstrong for a time ignored them because he couldn't tell what they were saying. Finally, after some weeks of hearing these incomprehensible yells, he turned to his bandmates and asked what people were calling out. When they told him "Hello Dolly!", he couldn't remember even having recorded the tune. They had to send away for the sheet music and re-learn the song before they could perform it live.