The melody of “Desafinado” uses chromatic neighbor tones. When you play it, lean into the dissonance slightly. Do not rush the half-step slides. The humor of the song comes from the tension between the "wrong" note and the "right" chord beneath it.
Here’s what I can do to help you find it : desafinado piano sheet music pdf
You can find various arrangements for piano, ranging from simple lead sheets to complex solo transcriptions. Desafinado | PDF - Scribd The melody of “Desafinado” uses chromatic neighbor tones