Is “Rocky” a Broadway box office contender?

Too soon to tell, but sales for the large-scale new musical’s initial string of previews suggest audiences are displaying curiosity about the tuner version of the pugilist romance.

“Rocky” logged $642,830 for six previews last week — far from a knockout number, but fairly consistent with the prior frame’s early numbers and a decent tally for an untested property that at first blush can raise some skepticism among theater purists. The musical’s no B.O. champion yet, but last week’s 88% attendance will likely kindle hope in the legiters in the show’s corner.

Industry types are keeping a close eye on “Rocky” as one of a number of big-title musicals on the competitive Broadway slate this spring. Also on that list is “The Bridges of Madison County” ($364,888), which managed to rise slightly in a week that accommodated press performances and a heavily comped opening (anomalously skedded the night before the actual press opening Feb. 20). Raves for lead performer Kelli O’Hara, even from the critics who were lukewarm on the show, likely helped prod sales, but it remains to be seen just how much they’ll spur the production’s somewhat sluggish momentum in the coming weeks.

“Aladdin” and “Bullets Over Broadway” are waiting in the wings to begin previews, but in the meantime “Beautiful” ($913,047) — which doesn’t have a title with pre-existing Hollywood cachet but comes with the brand-name appeal of the bio-musical’s subject, Carole King — is starting to look like it might be a sleeper. The production broke the house record at the Stephen Sondheim Theater for the second frame in a row last week, averaging attendance at 96% of capacity and a price paid per ticket of $116.33, a mark of solid demand.

Also doing well last week was “Cinderella” ($939,356), rising again on the backs of new stars Carly Rae Jepsen and, especially, Fran Drescher, whose fanbase of older-skewing females overlaps nicely with Broadway’s prime ticketbuying demo. On the other hand, “After Midnight” ($621,483), another tuner with a new star on board, hasn’t seen much of a boost from the addition of k.d. lang to the cast.

Among plays, Bryan Cranston topliner “All the Way” ($726,190) downticked a bit but still did well enough to top the chart among non-musicals, while the well-reviewed fall opener “The Glass Menagerie” ($652,206) saw B.O. spike with last-minute biz in its final frame on the boards. Dismal numbers at Yankees play “Bronx Bombers” ($140,446) confirm that producers made the right decision in posting a closing notice for March 2.

One play joined the fray last week, Tyne Daly starrer “Mothers and Sons” ($29,638 for one preview), and got a slow start at the Golden Theater.

Total Broadway cume was down about $650,000 to $20.5 million for 27 shows now running. Attendance climbed a bit to 208,637 (or 86% of capacity), a rise likely fueled by the mid-winter break in the academic calendars of some schools (including New York City public schools).

In the coming week, “Aladdin” throws its hat into the ring with “Rocky” and “Bridges,” as the latest Disney Theatrical Prods. outing starts previews Feb. 26.