“There’s no business like show business” isn’t just the title of a 1954 musical-comedy classic. Anyone who works in the biz will tell you that’s the truth, which is why Miami Theater Center is throwing a birthday bash for itself, the 10th Anniversary Gala, this Thursday. But the party isn’t just about touting the center’s accomplishments. MTC is transforming its main stage into an intimate cabaret-themed space and has lined up Tony Award-winning actress and singer Tonya Pinkins to perform a selection of Broadway favorites as a thank-you to all of those who have shown support during the past decade. The black-tie affair, which includes a sit-down dinner at 7 p.m. and an afterparty at 8:30 featuring a samba performance, dessert, dancing, and an open bar, commemorates the long way that MTC has come since it started in 2004 as the PlayGround Theatre.