Star Trek celebrates its fiftieth anniversary this year, which is ten times longer than the "five year mission" featured in the TV series. And while every fan has a favorite iteration (even though anything other than the original is clearly the wrong choice), most will agree that the music makes the show work. Think of the Kirk/Spock fight scene from "Amok Time" without that insistent score — it would lose so much tension. And music is what Star Trek: The Ultimate Voyage is all about. Justin Freer conducts a symphony orchestra key musical moments while scenes from all of the TV series and five of the films are shown on a 40-foot screen. Star Trek: The Ultimate Voyage starts at 7:30 p.m. tonight at the Fox Theatre (527 North Grand Boulevard; 314-534-1111 or www.fabulousfox.com). Tickets are $25 to $100.