"Summer Night" is a waltz arrangement of the Harry Warren composition featured on Holger Marjamaa's 2019 album Mostly Standards, showcasing the pianist's versatility in a multi-soloist setting. The 48-bar form in C minor at approximately 187 beats per minute unfolds with the graceful lilt characteristic of jazz waltzes. Trumpeter Benny Benack III takes the first two-chorus solo, his bright tone and melodic directness bringing warmth and energy to the waltz feel. Marjamaa follows with two choruses of his own, his piano improvisation combining rhythmic fluidity with harmonic depth as he navigates the extended form. The waltz time signature gives both soloists an opportunity to explore the rhythmic possibilities of three-quarter time, a context that can reveal different qualities in an improviser's musical personality than standard four-beat swing. Harry Warren, one of the most prolific and successful songwriters of the Golden Age of Hollywood, composed "Summer Night" as a contribution to the American popular songbook, and Marjamaa's arrangement honors the melody's romantic character while recasting it in a jazz waltz framework. The track demonstrates the collaborative spirit that characterizes Mostly Standards, with the soloists engaging in a musical conversation framed by the rhythm section's supportive accompaniment.