Floats and balloons were mustered early Thursday for a Macy’s Thanksgiving Day Parade that promised a mix of new attractions and longtime favorites, solemn tributes and lighthearted spectacle.

Carrying banners and flags, participants gathered on an unusually warm November morning near the start of the parade route. The lineup included three new balloons, 2,000 cheerleaders, 800 clowns, the Radio City Rockettes, and 11 marching bands — among them the Virginia Tech Regimental Band, playing in honor of the victims of last spring’s campus shooting.

The 81st annual parade was to start to a Michael Feinstein tune especially written for 600 kids from around the nation, whose opening number was choreographed by John Dietrich of the Rockettes.

The festivities began Wednesday night when workers inflated 11 giant helium balloons, including the new ones: William Steig’s swamp-loving ogre Shrek, Sesame Street’s fairy-in-training Abby Cadabby, and Hello Kitty Supercute, the cape- and tiara-wearing feline superhero.

The parade also marks one of two opportunities a year for Broadway to strut its stuff on national television. But for the cast of “Legally Blonde,” the parade is a showcase without a show.

The musical is one of more than two dozen productions shuttered by a Broadway stagehands strike. Its cast was set to appear in the parade, but the costumes and props were locked behind the stagehands’ picket lines.

Four Broadway shows — “Legally Blonde,” “Mary Poppins,” “Young Frankenstein,” and “Xanadu” — nabbed coveted positions in the parade, the only annual event besides the Tony Awards that provides a TV spotlight for the Great White Way.

But because of the stagehands’ contract dispute with the League of American Theatres and Producers, cast members of “Legally Blonde” won’t be able to use their costumes and props when they perform the show’s “What You Want.”

“We’re going to have a national spot on television, and we’re going to be half represented,” the show’s director and choreographer, Jerry Mitchell, said. “We’re going to be the only musical performing without our props and costumes, which I find very disheartening.”

The actors planned to use replacements, which most spectators likely won’t notice since the lead role involves a law student who loves to wear pink.

Because anyone appearing in the parade falls under a TV contract with the American Federation of Television and Radio Artists, “Legally Blonde” performers will not be crossing picket lines by marching, according to their union, Actors’ Equity.

The other Broadway three productions in the parade are not on strike because their theaters have separate contracts with the league.

Some 10,000 people will march this year, half of them Macy’s employees.

The parade will be televised nationally on NBC from 9 a.m. to noon in all time zones, with areas of the country not on Eastern time watching a taped version.