“Side project” isn’t an accurate name for a band whose members already play in six other bands (of which We Versus the Shark and Cinemechanica are arguably the most well-known). Pegasuses-XL seems more like a repository for whatever ideas its four members couldn’t integrate into their other bands. Their debut album, The Antiphon, is an intriguing mess that strongly recalls long-gone experimental hip-hoppers cLOUDDEAD. Its best songs share that group’s fondness for nubbly keyboards and logorrheic, adenoidal rapping. Pegasuses-XL are still math-rockers at heart, though, so their songs make much more use of live guitars and drums. Unfortunately, The Antiphon is poorly sequenced and often hook-less. The album begins and ends with its worst songs, and when a lone female voice appears to sing the chorus of tenth track “The Big Haunt”, it becomes a lucid respite from the nine unintelligible tracks that preceded it.