The Pearly Band is a group of musicians from Mary Poppins. They're all dressed up in pearl buttons and sing "Supercalifragilisticexpialidocious". A lady in a magenta dress plays the tambourine, a short man in a black suit plays the bass drum, a tall man in a black suit plays the bones, another short man in a black suit plays a stringy click instrument that looks like a banjo with a cymbal attached to it, and a lady in a blue dress plays the violin. Only the short man on the bass drum speaks.
The drummer and violinist also make a cameo appearance in 101 Dalmatians II: Patch's London Adventure: the violinist in a phone booth, and the drummer walking two Great Danes during the "Twilight Bark" scene.