Writing for french horn

[buckshead]

I have been looking through some scores lately and wondered if anyone knows the answer to the following. When writing for the 4 french horns, why would you ask for horn no 3 in a solo part, as against say no 1 ?

I realise this would make sense on a long piece to rest the players and share the load but why start with no 3 when the solo is only a few bars and the other horns aren't used again for quite a few bars. Wouldn't you expect no 1 to be the better player ? In a longer section I found equally odd placings 1 and 4 for example. Aren't all the horns the same ? Could one tell if 2 and 3 played instead on 1 and 4 ?

[TheFinaleGuru]

A good question. In a professional setting, while Horn 1 is likely to be the best player, all four would be considered of equal strength. The classical composers likely never wrote with the thought that "Horn 1 and 2 are strong, but 3 and 4, wow they're probably gonna be weak." Therefore, the composer can use whomever he wants for what purpose. To some extent, it's a guessing game why composers choose the personnel they do. Here are some possibilities and things to consider:
Horns in different keys. In classical pieces, you might have Horns in various keys (using different crooks). Today, they're likely all in F, but in an older score you might have Horns 1-2 in Eb and Horns 3-4 in C. In that case, Horn 3 might play a solo, b/c it's suited for that key. Also, you may/may not know that typically Horns 1/3 are seen as the "higher note" players and 2/4 being the "lower note" players. That stems from the way horns are interlocked in their scoring. Also, Horn 4 is traditionally the "low horn" player and great 4th horn players often can play extremely low.
Well, hope that helps some!

[buckshead]

Now you mention it I realise that 1 and 3 are high and 2 and 4 are low. Should have noticed that, its obvious. Might explain the solo on 3. Its simple when you know. The score in question was reasonably modern, 1905 ish