His most important works in this genre are the 24 preludes that cover all 24 major and minor keys.
These were all in different keys, none of which was C♯ minor, but it is not known whether he fully intended by this time to eventually complete the full complement of 24 preludes in different keys, to emulate earlier examples by Bach, Chopin, Alkan, Scriabin and others.
However, it was in keeping with the practice of the times to play selected pieces rather than entire lengthy works.
The complete 24 Preludes have been recorded by Vladimir Ashkenazy, Nikolai Lugansky, Sergio Fiorentino, Rustem Hayroudinoff, Dame Moura Lympany, Steven Osborne, Michael Ponti, Valentina Lisitsa, Alexis Weissenberg and others.
Hayroudinoff's Complete Preludes (Chandos Records) was selected by Classic FM Magazine as part of the ‘four discs essential Rachmaninoff collection’.