"This meant that a note had to be so indescribably tender and soft that it was only allowed to be thought of."
As Alex Ross (2007: 69, quoted in Toop 2016: 158) puts it: "The Joke went around that Webern had introduced the marking pensato: Don't play the note, only think it."
George Perle (1990: [page needed]), noting that "no composer has ever been more concrete, explicit, detailed, and subtle in his notation," argues that if Webern did use a pensato, it would have been a pitch "with all the attributes that give a note actuality: pitch, duration, mode of attack and release, timbre, intensity," and not a pitch class.
He also points to a "verifiable pensato" in the last bar of Alban Berg's Lyric Suite: "The instruments drop out one by one, the four parts converging into a single line that continues into an ostinato on the last two notes of the derived series and becomes inaudible on the penultimate note of the series, seemingly continuing into the silence beyond."
", then "morendo...*", then the asterisk reads: "*)bis zum völligen Verlöschen, daher die letzte Terz Des—F eventuell noch ein-, zweimal wiederholen.