In Week 7 (July 7-13), when most Broadway shows saw sales dip, the pair to post the largest gains both had current ties to the large or smallscreen.“Mamma Mia!” ($982,823), benefiting from a big-budget ad campaign for the movie adaptation that opens Friday, and “Legally Blonde” ($772,920), the focus of a reality casting skein airing on MTV, each rose by more than $70,000 at box office. Both jumps stood out in a frame in which most productions saw sales slip, and the handful to rise didn’t do so by much. Total box office slid about $450,000 to $18.4 million for 30 shows reporting (or $19.4 million including estimates for “Young Frankenstein”), with the July 6 closing of “Les Liaisons Dangereuses” contributing to the shortfall. Largest tumble of the sesh was taken by “Mary Poppins” ($848,216), down more than $100,000, with “Monty Python’s Spamalot” ($580,037) off by more than $75,000. Both “Chicago” ($468,098) and “Cirque Dreams Jungle Fantasy” ($479,811) slowed by more than $50,000, and “November” ($256,268) dropped around $45,000. In general, though, most declines weren’t dramatic. Only new show in the mix, “[title of show],” brought in $163,916 in its first full week of previews, playing to houses averaging 52% of capacity. Small-scale tuner opens Thursday. The 25 musicals grossed $16,363,488 for 88.8% of the Broadway total, with an attendance of 206,699 at 82.6% capacity and average paid admission of $79.17. The six plays grossed $2,070,696 for 11.2% of the Broadway total, with an attendance of 32,091 at 69.4% capacity and average paid admission of $64.53. Average paid admission was $77.20 for all shows.