Complex sentence: The group was under strong influence of neoromanticism in music and especially of foreign composers such as Richard Strauss, Richard Wagner and those belonging to The Mighty Handful group e.g. Modest Musorgski, Alexander Borodin and Nikolai Rimsky-Korsakov.
Split into simpler sentences: The group was under strong influence of neoromanticism in music and especially of foreign composers such as Richard Strauss and Richard Wagner. The composers had also strong ties to The Mighty Handful group of Russian composers, that included Modest Musorgski, Alexander Borodin and Nikolai Rimsky-Korsakov.