# Two of the same instruments in unison (intonation)



## MikeH (Jan 29, 2014)

(In a live situation) isn't it generally advisable to not do this unless it's a very rapid passage? I have been greatly warned about two oboes and two violins, but I'm wondering if something like two trumpets would be okay. Same with trombones. 

For example if I have four trombones and two musical lines, would it be better to give it to just two players or put two players on each line?


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## The Darris (Jan 29, 2014)

MikeH @ Wed Jan 29 said:


> (In a live situation) isn't it generally advisable to not do this unless it's a very rapid passage? I have been greatly warned about two oboes and two violins, but I'm wondering if something like two trumpets would be okay. Same with trombones.
> 
> For example if I have four trombones and two musical lines, would it be better to give it to just two players or put two players on each line?



Most orchestras use divisi sections that vary in sizes. It is solely up to how you want to orchestrate it from there. If you have 4 trombones then you will write with the idea that 4 trombones will be playing unless you want an a2 line or even a solo. Intonation is really only a huge problem in lesser skill leveled groups, (ie: high school, some college, etc).


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## Saxer (Feb 10, 2014)

i normally would not do unison between two violins or two oboes. inside a section it's no problem (middle voices in small divisi string groups etc). but i think that's the only exeption. all other instruments are ok á two. chamber orchestras have often two horns or two trumpets only. works fine.


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## MacQ (Feb 10, 2014)

It really depends on how good the players are, I think.

It's much less terrible writing for two violins or two oboes when they're not playing in their higher registers. The ear is really sensitive to that grinding pitch discrepancy (it's why horror clusters are so effective, I think). But having them play softer and lower can be a nice chorus colour, though personally I would almost always choose to divide my winds to reinforce thirds and 5ths.

Like in all things orchestration, it's really up to you and the conductor to decide in the end.


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## Hannes_F (Feb 10, 2014)

MikeH @ Wed Jan 29 said:


> (In a live situation) isn't it generally advisable to not do this unless it's a very rapid passage? I have been greatly warned about two oboes and two violins, but I'm wondering if something like two trumpets would be okay. Same with trombones.
> 
> For example if I have four trombones and two musical lines, would it be better to give it to just two players or put two players on each line?



2 Trumpets or 2 trombones in unisono are quite common, that is one reason why there are many sample patches recorded like that. The other practical reason for the usability of these a2 patches is that their sound has some natural phasing and therefore makes a better fade transition to another velocity layer than in the case of a solo trumpet or trombone. But apart from that their archetype comes from classical literature.


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## windshore (Feb 10, 2014)

I agree that writing for 2 of the same unison instruments can be trouble. It certainly can be stressful for the players. Because timbre is the same, the slightest difference in pitch or vibrato is amplified.

Of course you can find many instances of 2 instruments playing unison but as has been pointed out, it works fine within a section where they are teamed with another line. Again this is really only a problem in an exposed setting and tends to be more extreme in extreme registers.

The easy solution is to add one (or more) other instrument or have the 2 instruments play octaves rather than unison.


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## re-peat (Feb 12, 2014)

Or have them _not_ play in unison, *Giuco delle coppie*-wise.

_


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