Over the course of five albums, Ellen Allien has gone to great lengths to test minimal techno’s constraints. However, with her sixth album, Sool, Allien has taken an opposite route by relishing the genre limitations she once fought against. Produced with fellow Berlinette AGF, Sool takes the word “minimal” literally: tracks like “Einsteigen” and “Caress” are almost too delicate and airy to be considered songs. As such, much of the album comes off like an endless intro; the sounds never provide techno’s all-too-familiar foundation. While that can make for a bold scramble of expectations, ultimately, Sool comes off more like a mission statement than an engrossing listen.