However, Bach's best works in the form (by his own estimation) are assuredly the four "Orchester-Sinfonien mit zwölf obligaten Stimmen", Wq. 183, which, as their title suggests, were written with obbligato wind parts that are integral to the texture, rather than being added on to an older string symphony. The first symphony (D major) in the set has been particularly popular, seeing a continuous performance and publication tradition all the way through the 19th century, which makes it the earliest such symphony. Some of its more unusual features have been taken as characteristic of Bach's style: the work, although it is in D major, begins "on" a D major chord, which then turns into a D dominant-seventh chord, outlining "G" major. In fact, there is no cadence on D major (D major is not "confirmed" as the key of the piece) until the beginning of the recapitulation, quite late in the piece.