IMSLP Forums

Hi all,

I've got the score for Mozart's Piano Concerto in C Minor, Number 24. I really need some clarification on something to do with the key signature for the Corni in Es/Horn in Eb and the Trombe in C/Trumpet in C.

The concerto is in the key of C MInor which has three flats, the clarinet has one flat - I understand that perfectly - to be honest I've only started to find our about Bb and F instruments recently . What I don't understand is that the horn in Eb and the trumpet in C, have the same key signature which consists of no flats or sharps. How can instruments in Eb and C have the same key signature and also how can the trumpet be in C, and the key signature not designate C MInor?

Many thanks

The tendency for the transposing brass parts to orchestral works to not use a key signature is a relic of the days when they had no valves, meaning that in order to play in different keys you actually had to change the crook of the instrument. Because there were no accidentals available to them and they were pitched in the tonic key, there would never be any need for a key signature, and the convention stuck even with the introduction of valves. What notes are used in the trumpet part? If it's just C and G then there would be no reason to worry about the use of E natural vs. E flat (not that a natural trumpet in C could play an E flat in a useful octave anyway), even aside from the no-key-signature convention.

For Mozart of course it's not a relic -- the trumpet COULDN'T play outside the fundamentals. So being in C, it'll relate to C minor just fine (all C means is that it's notated at concert pitch, so a C will sound C....just fine when the only notes it can play are C and G outside of one E -- and since the trumpet is almost always used for fanfare-like statements it's rarely an issue).

As for the horn? Even if it were notated by key, it wouldn't change -- an Eb instrument adds three sharps, and C minor is three flats, so no sharps or flats is correct.

Just like a Bb clarinet will play with no sharps or flats if the key is G minor, etc.

Melodia wrote:Just like a Bb clarinet will play with no sharps or flats if the key is G minor, etc.

Can I raise you a seventh?

Melodia wrote:For Mozart of course it's not a relic

Yeah, but I'm assuming the parts used are not the original edition - more likely they're from the Breitkopf complete works edition, which was from the late 19th century - so it still kind of fits with the 'relic' thing.

Thanks for the replies!

Melodia wrote:For Mozart of course it's not a relic -- the trumpet COULDN'T play outside the fundamentals. So being in C, it'll relate to C minor just fine (all C means is that it's notated at concert pitch, so a C will sound C....just fine when the only notes it can play are C and G outside of one E -- and since the trumpet is almost always used for fanfare-like statements it's rarely an issue).

As for the horn? Even if it were notated by key, it wouldn't change -- an Eb instrument adds three sharps, and C minor is three flats, so no sharps or flats is correct.

Just like a Bb clarinet will play with no sharps or flats if the key is G minor, etc.

Oh I see, there wouldn't be any sharps and flats for Eb major/C minor, as it is an Eb instrument after all. I should have known that, I wasn't seeing the obvious link.

With the C trumpet in the concerto, can only play the natural notes F, G, C, D and not Bb, Ab, Eb is that right? The thing is, flute, oboe, bassoon are all C instruments (in this case), the trumpet is also a C instrument but it dosen't have any accidentals, though I see how it relates to C minor.

Say the concerto was in D minor, would it still have a blank key signature? Though I gather that today, the trumpet can play all the notes.

Thanks

KGill wrote:The tendency for the transposing brass parts to orchestral works to not use a key signature is a relic of the days when they had no valves, meaning that in order to play in different keys you actually had to change the crook of the instrument. Because there were no accidentals available to them and they were pitched in the tonic key, there would never be any need for a key signature, and the convention stuck even with the introduction of valves. What notes are used in the trumpet part? If it's just C and G then there would be no reason to worry about the use of E natural vs. E flat (not that a natural trumpet in C could play an E flat in a useful octave anyway), even aside from the no-key-signature convention.

Didn't know they didn't have valves. Back then, there would have been no accidentals no matter what key the composition was in, if it was in F# major, the C trumpet here couldn't do much anyway? IS the convention still relevant today, there would not be any accidentals notated for different keys?

Most of the notes which I can see are, C, G not much else at all. Its very sparse!

Thanks

moze wrote:... if it was in F# major, the C trumpet here couldn't do much anyway?

A natural trumpet would be able to play only those notes in the key of F# that are in its harmonic series, so if it were a C trumpet then only a couple notes in a reasonable range would even be halfway relevant (and they'd be out of tune). A pre-valve composition in F# would almost certainly use instruments in F# instead.

IS the convention still relevant today, there would not be any accidentals notated for different keys?

Not a horn or trumpet player so can't say with certainty, but I think that in modern orchestral works the convention still holds but for band stuff they now use key signatures like any other instrument. If I have this wrong then hopefully someone who knows better will correct me.

KGill wrote:

IS the convention still relevant today, there would not be any accidentals notated for different keys?

Not a horn or trumpet player so can't say with certainty, but I think that in modern orchestral works the convention still holds but for band stuff they now use key signatures like any other instrument. If I have this wrong then hopefully someone who knows better will correct me.

Correct. Trumpet and horn parts generally don't have key signatures. This doesn't apply to all brass though: trombones and tubas generally have key signatures. And for most modern parts that I've seen lately the horns have had key signatures so the rule isn't set in stone.

Didn't know they didn't have valves. Back then, there would have been no accidentals no matter what key the composition was in...

This isn't entirely true. Not having valves doesn't doesn't mean accidentals can't be used. B-flat, for example, is in the 7th harmonic in the harmonic series (though a bit out of tune). Also the pitch can be bent further with the lips and on the natural horn even further with the hand to the point that accidentals are necessary.

KGill wrote:

moze wrote:... A pre-valve composition in F# would almost certainly use instruments in F# instead.

I only know of one work in F# major or minor from the "pre-valve" days that actually uses brass instruments pitched in those keys. There may be others, but the most famous F# minor piece from any period is probably Haydn's Farewell Symphony (#45) and he uses for the most part 2 valveless ("natural") horns, one pitched in A and the other in E, in order to get enough useful notes in the harmonically complex passages during most of the symphony. The harmonically simpler minuet, however, is in F# MAJOR (5 sharps, string-player hell) and does use 2 F# horns, but only playing notes from tonic and dominant chords. There's a big, exposed solo for the horns at the start of the Trio section -- Haydn showing off the virtuosity of his orchestra, no doubt. I wonder if his audience was musically sophisticated enough to notice the bizarre key, though on period instruments the whole symphony probably sounded a little uneasy and tense, appropriately so, because of it.

--Sixtus

KGill wrote: Not a horn or trumpet player so can't say with certainty, but I think that in modern orchestral works the convention still holds but for band stuff they now use key signatures like any other instrument. If I have this wrong then hopefully someone who knows better will correct me.

I think I've seen trumpets use it where horns don't (though not the other way around).