Some of the most influential composers in Western music history include Johann Sebastian Bach, who laid the foundations for the Baroque period; Wolfgang Amadeus Mozart and Ludwig van Beethoven, who were key figures in the Classical era; and Frédéric Chopin and Richard Wagner, who were prominent in the Romantic period. Twentieth-century music saw the emergence of influential composers like Igor Stravinsky and Arnold Schoenberg, who pushed the boundaries of musical expression.