for Marie and Caroline, in addition to other piano duets. On his return from Zseliz, he took up residence with his friend Mayrhofer. During the early 1820s, Schubert was part of a close-knit circle of artists and students who had social gatherings together that became known as Schubertiads. Many of them took place in Ignaz von Sonnleithner's large apartment in the Gundelhof (Brandstätte 5, Vienna). The tight circle of friends with which Schubert surrounded himself was dealt a blow in early 1820. Schubert and four of his friends were arrested by the Austrian police, who (in the aftermath of the French Revolution and Napoleonic Wars) were on their guard against revolutionary activities and suspicious of any gathering of youth or students. One of Schubert's friends, Johann Senn, was put on trial, imprisoned for over a year, and then permanently forbidden to enter Vienna. The other four, including Schubert, were "severely reprimanded", in part for "inveighing against [officials] with insulting and opprobrious language". While Schubert never saw Senn again, he did set some of his poems, Selige Welt (D. 743) and Schwanengesang (D 744), to music. The incident may have played a role in a falling-out with Mayrhofer, with whom he was living at the time. Schubert, who was only a little more than five feet tall, was nicknamed "Schwammerl" by his friends, which Gibbs describes as translating to "Tubby" or "Little Mushroom". "Schwamm" is German (in the Austrian and Bavarian dialects) for mushroom; the ending "-erl" makes it a diminutive. Gibbs also claims he may have occasionally drunk to excess, noting that references to Schubert's heavy drinking "... come not only in later accounts, but also in documents dating from his lifetime." Musical maturity The compositions of 1819 and 1820 show a marked advance in development and maturity of style. The unfinished oratorio Lazarus (D. 689) was begun in February; later followed, among some smaller works, by the hymn "Der 23. Psalm" (D. 706), the octet "Gesang der Geister über den Wassern" (D. 714), the Quartettsatz in C minor (D. 703), and the Wanderer Fantasy in C major for piano (D. 760). In 1820, two of Schubert's operas were staged: Die Zwillingsbrüder (D. 647) appeared at the Theater am Kärntnertor on 14 June, and Die Zauberharfe (D. 644) appeared at the Theater an der Wien on 21 August. Hitherto, his larger compositions (apart from his masses) had been restricted to