Even in the 18th century, the concept of an insertion aria - here, a Haydn duet for use in Martín y Soler's opera Il burbero di buon cuore (The Good-Hearted Curmudgeon) - took a little explaining.

The best-loved piece of music can have a chequered history before it takes the form with which we’re most familiar: besides the complexities of the creative process itself, it may not be until the first performance that flaws come to light, resulting in revisions before the work is given another airing. In opera, this could go as far as the wholesale substitution of one musical number for another, even more so if an aria written for an original cast member turns out not to be suitable for a replacement further down the line. In other cases, entire scenes could be inserted to satisfy a dramatic need … or to placate a singer who insists they need a moment to shine.

The end result can be a work with all sorts of alternative content to choose from, Mozart’s Don Giovanni being a very good example of this. The most immediately obvious is when to end the opera: most productions conclude with the title character being dragged to Hell, in accordance with Mozart cutting the final scene (in which the remaining characters reflect on the moral) when Don Giovanni transferred from Prague to Vienna. This was, however, only one of many changes the composer made at the time, not all of which have generally stuck.

Chief among these is a duet in which the peasant-girl Zerlina ties Giovanni’s servant Leporello to a chair with the intention of torturing him, which adds nothing significant to the plot and is very rarely included today. This is to the benefit of ‘Mi tradi quell’alma ingrata’, a new aria for Elvira; this could also be left out with no detriment to the narrative, only it is a remarkably fine piece of music which captures her character to a tee. When it comes to Ottavio’s ‘Dalla sua pace’, however – intended as an alternative to his ‘Il mio tesoro’, both expressing his desire to support Anna, his almost-but-not-quite fiancée – some productions can’t bring themselves to favour one over the other, so room is often found for both.

Not that composers limited themselves to writing insertion arias (to use the correct terminology) for their own operas. There was also nothing to stop a singer who enjoyed a particularly fruitful relationship with a given composer from turning to them for a new showpiece. This could even happen repeatedly, as was the fate of Martín y Soler's 1786 opera Il burbero di buon cuore: prior to Haydn writing the duet pictured above for its production in London, Mozart had composed a pair of new arias for the opera for its 1789 revival. In truth, this was probably easier than asking Martín y Soler himself to do the honours, as he had long since left Vienna for St Petersburg, where he was working at the court of Catherine the Great.

Mozart had previously written ‘Popoli di Tessaglia’ for Aloysia Weber to sing in Gluck’s Alceste. He had once been in love with her (and would later become her brother-in-law), and if the fiendishly difficult music he composed for her is anything to go by – including two high Gs, higher even than what he would later write for the Queen of the Night in The Magic Flute – she must have been a truly exceptional singer. That said, even if Gluck’s opera had a place in opera houses’ repertoire today, they would be hard pushed to find someone to do justice to this aria: there was never really much chance of it being retained in Alceste in the long term. When it is performed today, it’s more often than not in a concert.

As such, it could be termed a concert aria, joining the subset of those never intended for use within an opera. There is again a very famous example by Mozart, Ch’io mi scordi di te being written as a gift for the soprano Nancy Storace (the first Susanna in The marriage of Figaro) when she left Vienna to return to London. In featuring a substantial solo piano part – which Mozart very likely played himself when it was premiered at her farewell concert – it is a celebration of their artistic collaboration, and would probably be performed more frequently if orchestral concerts with both a soprano and piano soloist were more common.

Other concert arias have tended to fare better. They include Haydn’s Scena di Berenice, Beethoven’s Ah, perfido! (for which Robin Johannsen joins the SCO at our Borrani & Beethoven concerts, 5-6 March) and Mendelssohn’s Infelice!, coincidentally all for soprano. One of the few exceptions is another one by Mozart, Per questa bella mano, for bass: another aria with a solo instrumental part, this time for double bass – which may again account for the rarity of its performances.

Ultimately, the only thing that really differentiates a concert aria from an orchestral song cycle is its duration. Even the longest of concert arias tends not to last much more than 10 minutes, whereas song cycles – typically made up of at least four individual movements – are invariably more substantial. The latter can therefore feel like better value for money, but like any piece within the larger body of an opera, a concert aria should feel complete in itself, encapsulating all the emotions of the character at that precise moment. To some extent, it’s the musical equivalent of a short story, presenting a very different challenge from writing a full-length opera or novel, but being a miniature doesn’t make it any less valid as an art form.