Staying Rachmaninoff-adjacent, as opposed to posting about Rachmaninoff directly: Rachmaninoff learned much from the great master of the Russia of his youth, Peter Ilich Tchaikovsky. Tchaikovsky met Rachmaninoff when the younger composer was still a teenaged student, and he gave young Sergei much encouragement and even requested work from him, such as four-hand piano arrangements of his ballets. Tchaikovsky could be a prickly critic of young Rachmaninoff’s early work, but he was nevertheless supportive, and the young composer was hoping for a more collaborative relationship with his elder master when Tchaikovsky sadly died of cholera.
I don’t know if this specific work of Tchaikovsky’s had any direct influence on Rachmaninoff, but you can still hear the brooding drama and the heartfelt lyricism here that would typify just about all of Rachmaninoff’s work.
Here is Tchaikovsky’s Romeo and Juliet overture.