Strings quivered. Notes shimmered. Meet best friends acclaimed composer Ludwig van Beethoven and bold female entrepreneur Nannette Streicher in this lively and lyrical nonfiction picture book. In a tall, narrow building on a wide avenue pianos plinked and plunked day and night. Everyone in quiet Augsburg knew the Stein home. What music! In 1787, aspiring yet unknown composer Ludwig van Beethoven arrives at young Nannette Stein’s home. What follows is a decades-long friendship that persists whether life hits a low or high note. Acclaimed nonfiction writer Laurie Lawlor deftly depicts how these two fascinating friends—a composer with hearing loss and a woman who became an innovative piano maker in a time that discouraged female entrepreneurship—fought the odds and worked together in perfect harmony.  The author of picture book biography Fearless World Traveler, Lawlor masterfully uses forgotten historical letters, a glossary, and rich back matter on both friends’ lives and art to introduce readers to the man behind the music, from his loud laughter to his crushing handshake.  Complete with Fearless World Traveler collaborator Becca Stadtlander’s intricate mixed-media artwork, What Music deftly dives into musical history–and herstory–in an intimate yet expansive picture book biography that hits just the right note.