The in-person portion of the 2021 Philadelphia Folk Festival has been called off.

The annual summer gathering was to be held Aug. 21-22 in a scaled-down, “pocket-sized edition” at the Spring Mountain ski area in Upper Salford Township rather than its traditional home at the nearby Old Pool Farm. It has been canceled due to concerns about the spread of the delta variant, organizers said Tuesday.

Instead, the festival will be held on the scheduled dates as a virtual, online-only event for the second year in a row.

“With health guidelines changing daily and the rise in COVID infections to their highest in months, coupled with the fact that PFF is a family event and that children are not able to be vaccinated, we have made the decision to cancel the in-person portion of the Festival,” the Philadelphia Folksong Society said in a statement.

The Folksong Society did not say which of the in-person performers would be part of the online-only festival. The in-person portion was scheduled to be headlined by Bettye LaVette and the David Bromberg Quintet. Scheduled acts included Katie Pruitt, Susan Werner, Dom Flemons, Dustbowl Revival, John Byrne, and Davina & the Vagabonds.

A spokesperson said that “new acts, international-partner shows, and more will be announced this Thursday.”

This was to be the 60th edition of the Folk Fest, which was cofounded in 1962 by folk DJ and longtime host Gene Shay, who died from complications of COVID-19 last year. Because of its smaller-than-usual nature, this year’s fest was being billed at the 59 1/2 Annual Pocket Sized Philadelphia Folk Festival.

All in-person ticket holders have been contacted by the Folksong Society and have been given the option to donate the cost of their tickets back to the Folksong Society or receive a full refund, organizers said. Tickets for the digital festival are available for sale at folkfest.org.