Pyotr Ilyich Tchaikovsky's Op. 9 comprises three appealing piano pieces, reflecting his mastery of melody and emotive writing. These works offer a good example of romantic piano miniatures with expressive depth.
Cultivate a rich tone and nuanced phrasing to convey the emotional content.
3 Pieces (Op.9) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
3 Pieces (Op.9) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.