Piano practice pieces

• Chopin's "Raindrop" and "Butterfly," e.g.
• Music school exercises
• Part of Paganini's oeuvre
• Technique-building pieces
• Pianists' dexterity improvers
• Exercise pieces
• Chopin's "Twelve Grand _____"

Wikipedia Word definitions in Wikipedia
The Études by Frédéric Chopin are three sets of solo studies for the piano published during the 1830s. There are twenty-seven compositions overall, comprising two separate collections of twelve, numbered Opus 10 and 25, and a set of three without opus number. ...