He started piano lessons at age five but took an interest in rock music as he grew older, and had his parents buy him albums by Yes, Genesis and King Crimson on the black market.

[1] When Khoroshev was 26, he relocated from Russia to the United States, initially to New York City before he settled in Boston, Massachusetts.

[1] When Yes keyboardist Rick Wakeman left the band in 1997, Anderson invited Khoroshev to an audition after listening to his demo tape.

After a shaky initial audition, Khoroshev was successful on his second attempt, after he was given extra time to learn his parts.

[1] Khoroshev joined the band as a side musician, playing keyboards on their 1997–1998 world tour promoting Open Your Eyes (1997).