Webern's compositions are concise, distilled, and select; just thirty-one of his compositions were published in his lifetime, and when Pierre Boulez later oversaw a project to record all of his compositions, including some of those without opus numbers, the results fit on just six CDs.[73] Although Webern's music changed over time, as is often the case over a long career, it is typified by very spartan textures, in which every note can be clearly heard; carefully chosen timbres, often resulting in very detailed instructions to the performers and use of extended instrumental techniques (flutter tonguing, col legno, and so on); wide-ranging melodic lines, often with leaps greater than an octave; and brevity: the Six Bagatelles for string quartet (1913), for instance, last about three minutes in total.[citation needed]