Weekend Two of the Austin City Limits Music Festival began Friday at Zilker Park. Some highlights:

1. Crowds grew gradually through the day as the 7:45 p.m. headlining set by Paul McCartney approached. The legendary Beatle had delighted Weekend One crowds with an oldies-heavy show; a similar set was expected Friday night, with a few songs likely swapped out.

2. Politics popped up a few times: David Byrne urged everyone to vote in the midterm elections, and British pop star Lily Allen dedicated her song — well, let's just call it "(Expletive) You" — to the president.

3. Sunny skies early gave way to a welcome blanket of clouds in the afternoon as temperatures topped out in the mid-80s. Weather might be the big story on Saturday: A significant chance of thunderstorms is forecast for late-morning, which might mean a repeat of last weekend's gate-entry delay. If you plan to arrive for the 11 a.m. opening, be prepared to possibly wait.

4. Saturday brings heavy rockers Metallica in the headlining spot, plus late addition Lil Wayne, pop band Chvrches, Weekend One highlight Brandi Carlile and more.

5. Like Friday, Saturday is sold out, but single-day tickets remain available for Sunday. The final day of the festival features headliner Travis Scott as well as Weekend One standouts Janelle Monae and St. Vincent.