Ambulance LTD performed under the moniker Impervious at Union Hall in Park Slope last night. It was a short set, with the band mainly testing new material, which a lot of fans have been skeptical about after most of the band left to form Red Romance. Singer/songwriter Marcus Congleton is the only member than remains from the lineup that created 2004′s critically acclaimed debut “LP.” Though the new songs didn’t seem fully realized yet, the foundation  of these songs was as solid as anything on “LP,” and stays true to their blend of dreamy Beatle-esque pop and shoegaze. Once the new lineup gets more gigs in, they’ll be back to being one of NYC’s best bands. Ambulance LTD will be back at Union Hall on Wednesday February 20, and this time it’ll be be under their real name. If you’re worried that they’re only playing new material, don’t b. They still managed to play a couple old ones last night, including the pop gem “Anecdote.”