A collection of pieces focusing on musical intervals themselves. It progressively expands the intervals one by one, from seconds to octaves, exploring the characteristics of each interval (including major and minor). The concept itself is familiar to pianists, even without citing Debussy's Etudes as an example, and offers no particular novelty. However, the collection's playful pieces, presented without any pretense, are truly remarkable. Each piece is titled with an English idiom containing a number. While all pieces are distinctive and engaging, the highlight is "Seventh Heaven," which focuses on the seventh interval. It is composed in the fusion style that was prevalent globally at the time. Many in Japan would also have been enthusiastic about fusion bands such as Casiopea and T-SQUARE. It is remarkably stylish and remains fresh even when played today. This serves as evidence of Rocherolle's proficiency not only in classical music but also in jazz and pop. The difficulty level ranges from approximately Czerny 30 to 40. Dedicated to Attica Aitkens.

• 1. Second Thoughts | Crisply, 4/4, B flat major
• 2. Third Time’s Charm | Slowly, 4/4, E minor
• 3. Fourth Dimension | Wistfully, 6/8, C major
• 4. Fifth Wheel | Fast, 4/4, F major
• 5. Sixth Sense | Brightly, 4/4, C major
• 6. Seventh Heaven | Easy-going, 4/4, F major
• 7. Figure Eighth | Fast waltz, 3/4, C major