* Operetta's lingering influence: The elegant, European-style operetta, with its elaborate costumes, romantic plots, and often lighthearted storylines, still held sway. Composers like Victor Herbert continued to produce popular works in this style. However, the conventions were starting to loosen.
* The rise of the "book musical": The 1910s saw the gradual development of the "book musical," where the musical numbers were more integrated into the plot, rather than simply being stand-alone acts. This integration, however, was still in its nascent stages. The plot usually remained fairly thin, serving primarily as a vehicle for the songs.
* Vaudeville's impact: Vaudeville's influence was undeniable. Many musical shows incorporated elements of vaudeville acts, including comedy routines, acrobatic performances, and solo musical numbers. Stars from vaudeville often transitioned to musical theatre.
* Early examples of integrated musicals: While not fully developed, shows started to experiment with more integrated narratives. This involved using the songs to advance the plot or develop characters, a significant departure from the loosely connected numbers of earlier operettas.
* Technological advancements: The development of better sound systems in theatres allowed for more elaborate musical scores and a greater range of vocal styles.
* Themes and Styles: While romantic plots were still common, the themes started to subtly diversify, reflecting the changing social climate of the era. However, political or socially controversial themes were still largely avoided.
* Notable composers and shows: While not as iconic as later eras, names like Victor Herbert, Jerome Kern, and Irving Berlin were already making their mark, contributing to the evolution of the form. Specific shows are harder to pinpoint as universally "defining" for the decade in the way some later musicals are, but they represented important stepping stones.
In short, the 1910s in musical theatre were a period of experimentation and transition. The foundation for the integrated, plot-driven musicals of the Golden Age was being laid, but the legacy of operetta and vaudeville was still very much present. It wasn't yet the polished, sophisticated art form we associate with Broadway, but it was a vital period in its development.