None of these recordings were particularly well engineered for their time, yet Mark Obert-Thorn wrings more sonic information from them than BMG’s over-processed transfers reveal. Working from immaculate commercial pressings, Obert-Thorn restores the bottom frequencies, which bring the Philadelphia Orchestra’s warm, lush sonority to the forefront without obliterating the bronze glitter of Rachmaninov’s enviable pianism. The master rarely touched his youthful First Concerto in his last performing years, yet he tears through the first movement cadenza and dashing finale like a whiz kid raring to show off his latest toy. Rachmaninov brings characteristic power and straightforward authority to his Paganini Rhapsody, and Stokowski responds in turn with full-bodied yet incisive podium work. Well played as his Fourth Concerto may be, the pianist/composer yields to the icy, demonic edge and bubbling detail Michelangeli brings to his classic, gorgeously recorded 1957 EMI version. Still, these are important recordings, and with Naxos’ budget price and high quality transfers, piano collectors need not hesitate.