Johann Gottlieb Karl Spazier (1771–1830) was a German composer and music educator associated primarily with the Classical and early Romantic periods. His work is often categorized within the genres of chamber music and symphonic compositions. Spazier is best known for his contributions to the development of the string quartet and piano music, although he was not as widely recognized as his contemporaries. Notable works include his string quartets and piano sonatas, which reflect the stylistic transitions of his time, blending classical forms with emerging romantic sensibilities. Additionally, he composed several orchestral works, contributing to the broader repertoire of 18th-century German music. Spazier's impact on music lies in his role as a bridge between the Classical tradition and the Romantic movement, influencing subsequent composers through his innovative approaches to harmony and thematic development. His teaching and writings on music theory also helped shape the understanding of music composition during his era. While not as prominent in the historical canon as figures like Beethoven or Schubert, Spazier remains a noteworthy figure for his contributions to the evolution of chamber music and his influence on music education.