As a companion piece to their justly lauded 2015 LP The Sovereign Self, Glaswegian adventurists Trembling Bells offer up the seven-track mini-album Wide Majestic Aire. Named for Yorkshire's River Aire, which runs through bandleader/drummer Alex Neilson's hometown of Leeds, this release expands upon The Sovereign Self's peculiar amalgam of classic U.K. folk, psychedelia, early music, prog rock, and choral music. Through the dulcet voice of singer, keyboardist, and guitarist Lavinia Blackwell, Neilson's songs explore the territories of his life from the banks of the Aire to the Scottish Isle of Bute to the historic hutting community outside of Carbeth. As a songwriter, Neilson's vision seems singular and purposeful, but the musical presentation of Trembling Bells has always been a collective effort whose antennae attract a wild assortment of sounds and tones. Sometimes shambling through their own complex arrangements, they resemble pioneers of the U.K. folk-rock movement from Shirley Collins to Comus, channeling ancient traditions through creative flights of fancy that could almost come across as feral if they weren't so resolutely British. The standouts here are the title track and its Northern colleague "Swallows of Carbeth," two sprawling odes whose warm sentiments and soaring melodies veer into the dreamy realm of Sandy Denny's classic "Listen, Listen." The gorgeous pump organ/fiddle ballad "I Love Bute" seems to have more in common with the repertoire of the Crying Lion, the choral group he and Blackwell formed in 2014. It's true that Trembling Bells are an acquired taste, living far outside of the U.K.'s indie norm, but Wide Majestic Aire has heart and imagination to spare, adding yet another colorful feather to their cap.