Is there a soloist?

[Gauk]

Imagine the following: you have just turned on the radio and you hear the start of an unfamiliar orchestral work in an early romantic style. You missed the announcer (and we will assume you can't consult the programme schedule). A few minutes in and it is clear that this a first movement sonata allegro. Given the period, it could be a symphony (or even an overture), but then again, it could be a concerto, since most likely the soloist will not appear until the exposition repeat.

Question: is it possible to detect that it is the opening of a concerto before the soloist enters, just from the character of the music?

I sometimes feel that it is, though I couldn't give a technical explanation of how. Possibly in the case of a concerto the orchestral statement of the exposition will be less dramatic than would be the case in a symphony, since the fireworks await the soloist's entry. Possibly also one can intuitively feel that the material being introduced is pianistically conceived (in the case of a piano concerto), or would fit well with some other solo instrument.

Any thoughts?

[eschiss1]

Well, should make a distinction.  A first movement of a concerto, especially the form favored, with variations, by Mozart, Beethoven and Brahms, is not, exactly, a sonata-allegro. It's a (usually orchestra-only) tutti preceding a sonata-allegro, more or less, and that's not the same thing.
The function of the tutti isn't to display the work's themes like the overture to a Broadway play - there's too many counterexamples in their concertos to say that - but it's fair to say that it does have a sort of other function; to paraphrase a few other functions, you have an orchestra there (usually- some of these concertos can be played just with string quartet); they're being paid; in some of the rest of the work, unless (as in some of Mozart's concertos, e.g. the C minor, and others... the G major also I'd say) the composer is especially adept at balance and dialogue between the solo and the orchestra, they're going to spend a goodly amount of time there just providing harmonic support. This tutti is their one time to shine (not counting the end of the first movement, and maybe the beginning of the second, sometimes.) Again, with exceptions, always (but even then, Beethoven 4 e.g., the piano disappears for a fair amount of time after its initial contribution, and the work would not be the same without that B major orchestral response...)

Also, a symphonic opening statement is more likely than a concerto tutti to modulate and stay in different keys (indeed, arguably sonata form is more about opposing two or more large groups of themes each centered around different keys- it's not even really essential that the themes be that different, but it _is_ essential that the keys be different. Here's where concerto tuttis that modulate even briefly, even not long enough to really unsettle the ear - Beethoven 3, Mozart 14 (14 is one of my favorites among those concertos... ) - can confuse the ear well before the soloist enters.)  Generally, a symphonic opening section is- I won't say thing in itself, because that's precisely one thing it isn't; it ends in a different key so that the next part of the movement (the development, the Durchfuhrung, whatever) can return it to (almost always, anyway...) the home key - actually-- hrm.

The concerto "tutti" has also been described as a "processional". Is that word suggestive where the above tripe might just confuse, for which apologies?...

Concertos with no opening "tutti" at all have for some of the authors I'm paraphrasing (even though they're tarring with the same brush concertos by Paganini, Schumann and Mendelssohn, and they regretfully know it) something more of the feeling of showpieces rather than works that are, in some of these cases, also masterpieces at least in organizational strength...

[JimL]

If it is in Classical form, there will be no modulation in the orchestral exposition between the first and second subjects.  The modulatory transition in a concerto was reserved for the first solo.  If you can't detect the difference in key (or lack thereof), the transition in a concerto tutti would naturally be more concise due to the lack of modulation.  In a symphony exposition, there would be less of a sense of one idea following another and more of a sense of transition and progression.  However, the further one gets into the Romantic era the less adherence to Classical form there is.  Often, the exposition will be monothematic (the 5th Violin Concerto of Ferdinand David, the Reinecke 1st Piano Concerto, Violin Concerto, Harp Concerto) or fused (the mature Mendelssohn concertos for piano and violin, Schumann Piano Concerto, Draeseke Piano Concerto, Hiller Piano Concertos 2 & 3, etc.) 

As Eric mentioned, the opening tutti is NOT the same as a symphonic exposition.  If it were, the solo would replay it verbatim during its "repeat".

[eschiss1]

Jim- there will usually be no such modulation (there were some exceptions), but I don't think anyone had written down these rules at the time. And the solo entry/solo section's relation to the opening tutti could be near-verbatim (Mozart 23, K488) to, in some of Mozart's and others' concertos, very... tenuous!!
But I was deliberately not counting/speaking of concertos without any tutti at all, though also in part because the opening question of the thread wouldn't apply, presumably- it would I'm guessing be pretty obvious there's a soloist, unless there's a really substantial section in those concertos without a soloist, but that's another issue. (I know some of them fairly well, but not others, e.g. not yet the Hiller or the Reinecke violin or harp concertos..., though I may be able to fix that fairly easily...)

[JimL]

There are always exceptions.  Mozart's K411, does have a modulation in the opening tutti, and nearly all minor-key Classical concertos did as well, as the secondary theme was almost always in the relative major.  Even many of the concertos with early solo entries (e.g. Beethoven PCs 4 & 5) had full-scale tuttis for the orchestra afterwards, although, in the case of the 4th concerto, Beethoven withheld an entire theme from the secondary group until after the solo entry (although it is introduced by the orchestra at that point.)

[eschiss1]

Though this stretches us back to Mozart, someone (Tovey?) said of his 15-odd mature concertos that each of them has a unique feature affecting a large-scale aspect of its form, or something like that. Difficult to do, difficult to avoid sameness in that way, especially when so many of them were written in 1784 alone... I appreciate that sort of thing from a composer and understand why Alfred Einstein thought the piano concertos, not his symphonies, were likely the best part of his purely instrumental (that is, non-vocal) output, and why back when they were much less known (1939, rev.1964) Girdlestone devoted several editions of a book just to Mozart's Piano Concertos (or Mozart, and his Piano Concertos, in a later edition, expanding the book to fit the larger-themed title.)

There weren't that many Romantic composers who held to that notion of the concerto, especially after Mendelssohn et al suggested doing away with the tutti; Brahms was one, with variations but I think keeping to the essential idea (a big though mostly static - not as much so as in Mozart, this is the Romantic era - orchestral procession preceding the "main" solo entry) - in all four of his concertos.   

Hrm. Martucci 2 doesn't qualify unfortunately (rather wish it did) since after the piano cadenza the piano stays around- sometimes accompanying the orchestra, but not silent, no tutti. Anyone else, I wonder? Quite possibly, quite possibly...

[JimL]

In a similar vein to the Martucci, probably the best example of a fused exposition is the Raff PC, where, after exposing the principal subject the piano plays accompaniment through the entire orchestral exposition of the theme, albeit as an inner voice within the orchestra.

[eschiss1]

Have to check, but yes, I think Elgar's violin concerto begins traditionally enough. Which I guess returns one to the opening question- on an "innocent ear" listening, dropped in on that piece or another, could one tell which are the (more or less, give or take, post-Baroque traditionally-formed) concertos and which, the (fairly traditional-in-form) symphonies...

[TerraEpon]

Incidently, the proper name for this form is "Double Exposition Form"....because there's two separately composer expositions, instead of one that's just repeated.

[Gauk]

By the way, I have conducted the following experiment with roughly 30 professional musicians: can one ascertain a concerto's solo instrument solely by the orchestral music that precedes it. It's a fun thing to try, but I'm afraid the overall answer is "no."

Thanks!