Hi,
does anyone know about Bass clef for horn, because recently came across some music by Anton Horner which had 4 leger lines in the bass clef! I mean, I know what notes they are as I play piano as well, but how do you get these notes as they ave incredibly low on any instrument!

jorde,
Trying to understand what the composer wants is sometimes difficult. If you do not have a good music theory/history knowledge it's hard to know. What you can do is this . . . .

If the part goes down below the bass clef it is likely old notation, so read it up an octave. The other thing you can do is look at the other horn parts. If you are playing 3rd what does the 4th part look like? that will help you also. If you can't figure it out for sure ask the conductor. The conductor can look at all the parts in the score and figure out what yours is supposed to be.

Even if you know all the rules it doesn't mean the composer does. I recently did a concert where the composer had lots of ledger lines above the bass clef. I assumed it was new notation (especially since it was written in 1996) but my second horn player (who is a professional editor) said it sounded funny and wondered if it shouldn't be read as old notation. He checked the score and found out it was old notation. So I was actually playing a "D" second line from the top treble clef, even though it was written in bass clef.

Hope this helps you.