If you attended Built to Spill’s 1999 swing through the Showbox at the Market, to where they return this Friday and Saturday, you were privy to a bit of history, as the majority of the material used on the band’s 2000 live album was recorded then and there. I was fortunate enough to be in the audience that night, and the feeling walking out onto First Avenue was every bit as electric as it should have been.Not so Saturday night at Portland’s Crystal Ballroom, where Calvin Johnson joined BTS onstage for an unannounced Halo Benders reunion during an extended encore that had the potential to elicit a similarly enthusiastic reaction.You’d think the pairing of a lo-fi legend like Johnson (Beat Happening) would be like catnip to a Northwest indie rock crowd. Not quite–BTS’s main set was too short (45 minutes), and Johnson’s goofy demeanor didn’t go over as well in the Crystal Ballroom’s spacious confines as it might have in, say, the Croc, and the Halo Benders’ simpler, punky tunes don’t pair especially well with the jammed-out majesty of Built to Spill’s. (By the by, anti-McMenamin’s sentiment in Portland is about tantamount to Starbucks hatred in Seattle.)The encore lasted about six songs, the completion of each causing an ever greater number of attendees to head for the exits. For many, it was an incredibly disappointing showing from one of America’s greatest live bands (that’d be Built to Spill, not the Halo Benders). Ironically, BTS probably thought they were giving people a treat. Too bad it went down so bitterly.