Counting back from her breakthrough album (1963’s The Barbra Streisand Album) and stage role (Funny Girl, 1964), it only took Barbra Streisand half a century to perform in the Bayou City. That she’s coming here now still doesn’t quite seem real, as if one of the demigods from the Olympus of Old Show Business accidentally hired a travel agent keen on Southwest Airlines. But that perspective tends to gloss over what an enormous shadow Streisand, who was hailed by no less than Beyoncé at the 2008 Kennedy Center Honors, still casts over the American performing arts. Even discounting the poolhouses full of trophies she’s won (14 Grammys chief among them), Streisand continues to matter where it counts — the cash register. Her two most recent albums, 2014’s Partners and this summer’s Encore: Movie Partners Sing Broadway, both debuted at No. 1. (Skeptics among you who foolishly dismiss her as a voice of yesteryear are invited to peek at the secondary StubHub market.) Finally, her lack of experience as a touring artist hardly means the production won’t be first class all the way; even then, it still may not be up to the standards demanded by Streisand’s powerhouse yet near-robotically precise voice.