“Mamma Mia!” — here you go again.

Special Labor Day sing-alongs for Universal’s bigscreen musical adaptation “Mamma Mia!” scored bigtime, with the film actually enjoying a 2% bump in ticket sales over the holiday weekend. That’s impressive, considering the pic was in its seventh sesh.

U held the sing-alongs in 299 theaters, out of a total theater count of 1,968. Ticket sales for those runs amounted to 20% of the entire Labor Day gross, or roughly $1.2 million.

“That’s a pretty good equation,” said Nikki Rocco, Universal’s prexy of domestic distribution.

For the weekend overall, “Mamma Mia!” grossed an estimated $5.8 million from 1,968 theaters for a hearty cume of $132.9 million. Film came in at No. 8.

Sing-alongs are nothing new. Last summer, New Line held sing-alongs for “Hairspray” (which cumed $118.9 million domestically), but they weren’t quite as successful. That could be because “Mamma Mia!’s” Abba tunes are more popular.

When it comes to box office, it seems every note counts.