An online french horn that sounds like one
Most online instruments are a synthesiser with a picture on top. This one plays recordings of a real french horn, so the attack, the tone and the decay are the instrument's own. The french horn is the brass instrument that blends best with the woodwinds and the strings, warm rather than bright.
A short history of the french horn
The horn descends from the hunting horn. Valves arrived in the 1810s; before that, players changed notes with their lips and by moving the hand in the bell.
From the keyboard to the real instrument
A real french horn is written in treble clef (bass clef down low), written a fifth higher than it sounds. The keyboard here plays the sounding notes, so a melody you find by ear is the melody you hear. To go further, the free sheet music and chord pages work with any instrument you can read music on.