The World Series of Rock was a summer concert series held at the old Cleveland Municipal Stadium from 1974-1980. Co-sponsored by Belkin Productions and WMMS, each concert featured multiple acts throughout the day. The Rolling Stones played it twice ('75 and '78) as did The Beach Boys ('74 and '75). Other major acts to play included Santana, Aerosmith, The Cars, Fleetwood Mac, ELO, The Michael Stanley Band, and more.
The sweatshirt is great, but the image on the website needs to be updated. A short sleeved shirt is shown and I think that led to confusion with my initial order.