Konyus's Op. 15 presents two melodious pieces in the style of late Romantic Russian composers. They are known for their warm emotional content and accessible harmonic language.
Achieving a singing tone and carefully shaping the melodic phrases are key to capturing the pieces' expressive character.
2 Mélodies (Op.15) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
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.
A typical performance of 2 Mélodies (Op.15) lasts about 3 minutes.
2 Mélodies (Op.15) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.