The first Jazz Fest lineup included Mahalia Jackson (who was not booked, but simply heard about the Festival and showed up to sing), the Preservation Hall Jazz Band, Duke Ellington, Pete Fountain, Al Hirt, Clifton Chenier, Fats Domino, and The Meters This first lineup received an audience of 350 people, but the numbers grew every year, especially after the introduction of a limited edition silkscreen poster series in 1975. By the end of the 1980s, attendance peaked at 300,000. In 2001, when Louis Armstrong's centennial was celebrated, 650,000 people attended. The poster series has been very popular with collectors. The first poster was designed by Sharon Dinkins and Thorn Grafton. Posters feature a performer or the overall theme of the Festival, and all posters are commissioned by the Festival. In 1998, the Festival added the Congo Square poster series. Artists such as George Dureau, James Michalopoulos, George Rodrigue, Douglas Bourgeois, Duke Jupiter, John Scott, and Bill Hemmerling have been designers of the official festival poster. Congo Square posters have been created by Aziz Diagne, Elizabeth Catlett, Bill Pajaud, and Terrance Osborne. Osborne designed the poster for 2012 (as well as the 2007 and 2010 posters), which featured Trombone Shorty.