Louis Armstrong nicknamed Satchmo and Pops, was a charismatic, innovative performer whose inspired, improvised soloing was the main influence for a fundamental change in jazz, shifting its focus from collective melodic playing, often arranged in one way or another, to the solo player and improvised soloing. One of the most famous jazz musicians of the 20th century, he first achieved fame as a cornet player, later on switching to trumpet, but toward the end of his career he was best known as a vocalist and became one of the most influential jazz singers.
