In February 1920, Kosenko married Angelina, née Kanepp. His love and deep admiration for her was such that he used to write to her almost everyday and was disappointed if for any reason she could not reply to him as fast as he wished. The pieces created between 1919 and 1924 convey deep lyrical feelings, hence the reason he dedicated almost all of his output to her. In September 1922, Kosenko gave his first concert, attended by his family and close friends, traveling to Moscow the following year to meet with composers and musicians. By this time he was allowed by the Russian Association of Proletarian Musicians to have his first piano compositions published. This period that Kosenko spend in Zhytomyr was one of the richest in his musical career for he perfected his own artistic style in instrumental, vocal and chamber music; genres in which he was very active at that time. There, he authored a large number of piano pieces, over twenty romances, violin and cello sonatas, works for children, and music for plays. He was also heavily involved in a myriad of musical activities such as the creation of a music society, concert appearances, the organization of his piano chamber trio, vocal quartets and even a symphony orchestra, besides serving as accompanist player for different ensembles in the musical life of the city. In 1921, Kosenko and his fellow musicians founded the "Leontovych Musical Society." In September 1922, he gave his debut in Zhytomyr, performing his own compositions. Two years later, he was invited to Moscow for a recital at the Association for Contemporary Music, where he met with composers and musicians. During this period, Kosenko's piano works were published for the first time. He then performed as a virtuoso pianist in recitals and formed a piano trio along with violinist Volodymyr Skorokhod and cellist Vasyly Kolomyitsev, giving over one hundred free concerts throughout UkSSR between 1923 and 1929. In 1927, Kosenko was invited by the Association of the Proletarian Musicians of Ukrainian SSR to give a concert in Kharkiv, the capital of the Ukrainian SSR at the time. This same association invited him again in 1928 and 1929. Kosenko began giving concerts in Kharkiv, Kiev, Dnipropetrovsk, Luhansk, and nearby cities. The programme of the concerts included compositions by Ukrainian composers Borys Lyatoshynsky, Levko Revutskiy, and Pylyp Kozytskiy.