Unlike what the forefathers of the Tracht movement postulated, there has never been one certain traditional costume, not even for one clearly defined region.
What is traditional costume, anyway? There is no garment that was handed down through generations. Everything changed according to the fashion imported from whatever country was currently the leader of fashion. It was first introduced by the nobility and with a certain time lag, it appeared in citizens', then even in rural costume. This can be seen in pictures where e.g.
The time lag, which obviously was about 50 years at first, became shorter until the very early 19h century when costume items based on the fashion of decades ago, such as the Mieder (derived from 18th century stays) incorporated current fashion by developing a high Empire (Regency) waist.
Munich Tracht as it is known today developed during the early years of the 19th century. At first it reflected late 18th century and Empire traits, then developed into its height by incorporating the Biedermeier fashion, only to dissolve into "normal" fashion around the mid 19th century. It almost became lost, but then people started a re-creation movement based on the version that had last been distinctive, the one of 1825-1835. During those years, the Munich ladies' costume had been at its most attractive and regionally distinctive and was therefore well documented.
Speaking of region: Munich was much smaller then that it is now. A matter of course, you might think, but one tends to forget. Places that are now considered pretty central, such as Schwabing, Neuhausen and Haidhausen, were villages inhabited by peasants, well outside city limits, and did not become incorporated until the very late 19th century. The city of Munich had been a distinct legal and cultural entity, protected by city walls dating from 12th century, so its costume was also different from that of the surrounding villages.
Early 19th century commoners' costume was frozen in time because of its distinctness, the amount of documentation and not the least because of its elegance. Now it is regarded as the traditional costume of Munich. The unique clothing items developed during that time include the Spenzer, the Mieder, and - most distinctive of all - the Riegelhaube.
But what was there before 1800? Accompany me on a research journey, if you please....