The Weather: The daytime high is expected to reach 91 and an Air Quality Action Day has been declared. The festival opens at 5 p.m. with a chance of thunderstorms before 8 p.m. -- a 30 percent chance of rain, according to the National Weather Service.

The Headliner: Young the Giant, alternative rockers from Irvine, Calif., with special guest Portugal and opening act White Rabbits. Tickets at $34 and $24 are still available. Gates to the Sands Steel Stage at PNC Plaza open at 6 p.m. Show starts at 7.

The Highlight: Musikfest’s opening ceremonies will include the singing of the National Anthem by students from The Lesson Center, an invocation and sacred performance by the Tibetan Monks of the Drepung Loseling Monastery and a special tribute to longtime festival and ArtsQuest benefactor Marlene “Linny” Fowler. It all starts at 6 p.m. at Americaplatz – a.k.a. the Levitt Pavilion at SteelStacks.

The Best of the Free Platzes: Easton singer-songwriter Brittany Ann christens the new Martin Guitar Lyrikplatz in the Frank Banko Alehouse Theater at SteelStacks at 6 p.m.; local favorites Zen for Primates take the Liederplatz stage at 9 p.m.,and The Royal Southern Brotherhood (Americaplatz, 9:30 p.m.) features some honest-to-goodness southern rock n’ blues royalty, including Cyril Neville of The Neville Brothers and Devon Allman, son of Gregg Allman of The Allman Brothers.

Musikfest After Hours: Late night comedy with stand up comic Jim Tews, 11 p.m. at the Musikfest Café. Tickets are $5; The Toga Party Band plays at the Mural Club in the Historic Hotel Bethlehem from 9 p.m. until 1 a.m.; the funk/jam band Pendulum Duo plays at The Wooden Match (the former Main Street Depot) at 61 W. Lehigh St., from 10 p.m. to 1 a.m.