Complex sentence: Lyubov consulted with her nephew (by marriage) Alexander Siloti, already an accomplished pianist studying under Franz Liszt, who, after appraising his cousin's pianism and listening skills, recommended that Sergei go to his own original teacher and disciplinarian, Nikolai Zverev.
Split into simpler sentences: Lyubov consulted with her nephew (by marriage) Alexander Siloti, already an accomplished pianist studying under Franz Liszt. After appraising his cousin's pianism and listening skills, Siloti recommended that Sergei go to his own original teacher and disciplinarian, Nikolai Zverev.