While thinking about improvisation, about Schubert sitting at the piano playing while his friends danced, I realized that the piano permitted the sound of the waltz that would have been most familiar to people in Vienna about 1800 -- two violins and bass -- to be transferred from tavern or restaurant to the home.
-- and added this more recently (5-19-10): Litschauer and Deutsch give an example of this texture (44); so does Rainer Gstrein (82) .
And now I add this: Alexander Weinmann's Verzeichniss for Johann Strauss, sr. & jr., shows that the elder's early compositions were published in one or more of the following formats: piano solo, piano four-hands, violin and piano, 2 violins and bass, guitar, flute solo, csakan [Hungarian flute] solo, and orchestra. Beginning with Op. 56 (1832), "2 violins and bass" was replaced by 3 violins and bass, but as 2 violins, violin 3 ad libitum, and bass. Only with a handful of Strauss's last works was the "standard" string quartet specified instead: Opp. 225 (1848), 232, 237, and 241 (1849).
References:
Litschauer, Walburga, and Walter Deutsch. Schubert und das Tanzvergnügen. Vienna: Holzhausen, 1997.
Gstrein, Rainer, "Ländliche und urbane Tanzmusik im Biedermeier in Österreich." In Boisits, Barbara, and Klaus Hubmann. Tanz im Biedermeier: Ausdruck des Lebensgefühls einer Epoche, 73-87. Proceedings from the Symposium Musizierpraxis im Biedermeier: Tanzmusik im ländlichen und städtischen Bereich, Graz, Austria, 26.-27. März 2004. Series: Neue Beiträge zur Aufführungspraxis, vol. 6. Vienna : Mille Tre Verlag Robert Schächter, 2006.
Weinmann, Alexander. Verzeichnis sämtlicher Werke von Johann Strauss, Vater und Sohn. Series: Beiträge zur Geschichte des Alt-Wiener Musikverlages. Reihe l: Komponisten, Folge 2.
Wien: Musikverlag L. Krenn [1956].
