The romantic synth sounds of Future Islands have soared to new heights since the group’s formation in 2006. Its 2010 breakthrough disc, “In Evening Air,” shot the band into indie-lovers’ hearts and earned it coverage from numerous media outlets and regular spots on best-of lists. Last year’s “On the Water” fleshed out the group’s sound with the additions of cello, violin and field recordings, making it its most ambitious release to date and one that rewards repeat listens. Future Islands performs at the Camel on Monday, Jan. 23, at 8 p.m. $10. 353-4901.