Replacements or substitutions of personnel are nothing unusual in the music business.

If you have an orchestra of between 70 and 90 players, somebody's always going to be off or indisposed. It's commonplace to see guest principals step in if a section leader is ill or even just has the day off. Even if it's the conductor or soloist who's ill, they too can be replaced, and there are famous stories about replacement conductors taking over a programme and actually learning a new or unfamiliar work overnight to direct a performance of it the following evening in order to preserve the original programme. If singers are involved, that can be trickier. One sniffle, one tickle in the throat and an administration can find itself in trouble. And that's a different can of worms.

But the BBC SSO recently faced an entirely different issue in relation to its forthcoming Afternoon Performance concert on Thursday April 23 at 2pm in the City Hall, the last event in the current series of these extremely popular concerts. It was going to be a very different presentation. No conductor was involved. Instead, Laura Samuel, violinist and leader of the SSO, was going to direct her colleagues from the violin in a programme of music by Telemann, Haydn, Mozart and Beethoven that would feature not only Samuel herself as leader, but also bring into the spotlight some of her fellow section-principals. An intimate, engaging and entertaining afternoon was on the cards.

Then Laura Samuel slipped on ice, fell and broke her wrist. She is totally out of commission until the wrist mends. So the BBC SSO has done two things. The scheduled programme was Samuel's concept. She is the only full-time leader the SSO has. This was her programme, featuring her fellow principals. So the BBC has wisely lifted that programme - lock, stock, barrel and Samuel - and transplanted it wholesale into next season, where it has been scheduled for performance in a little under a year, in March 2016.

And that, of course, left a potential hole in the SSO's concert schedule on Thursday 23, for which tickets were already on sale. So the BBC SSO (though I don't know the day-by-day logistics of the operation) brought forward another project, already on the back burner, and slotted it into the schedule for that afternoon, completely changing the focus and point of the concert. And it is a clever, strategically timed event that will result in one of the most intriguing concerts of the season, though a superficial glance at the restructured programme might not suggest that.

The concert, which will now have a conductor in the person of Michael Collins, best-known as a star clarinettist, will open with the ballet music from Mozart's opera Idomeneo, follow that with a performance of the Violin Concerto by Scottish composer Erik Chisholm (the 50th anniversary of whose death falls this year) then conclude with a performance of Bartok's Second Suite for orchestra. And that lot, you might think, looks like a bit of a mixture-maxture, without much in the way of coherence or integration. In fact, quite the opposite is the case, and the unifying element in the programme is Erik Chisholm himself.

Chisholm, who was born in 1904, was a Glasgow man: he lived on University Avenue for many years. He was a pianist, conductor, composer and activist in music. He conducted the UK premiere of Idomeneo with Glasgow Grand Opera Society in 1934, before it was considered a work of any great significance; and the connection is thus made with the new SSO programme, which will open with the Idomeneo ballet music.

Chisholm was also passionate about the promotion of modern music: a man clearly of considerable influence, he founded an Active Society for the Propagation of Contemporary Music. He it was who brought Bela Bartok to Glasgow to give recitals of his own music in 1932 and 1933 (another Chisholm connection with the SSO programme on April 23, where the orchestra will play Bartok's Second Suite). Chisholm also brought composers Szymanowski, Hindemith, Walton and Bax to the city.

And, as a composer, Chisholm will have his days in the sun with the first performance in more than 60 years of his Violin Concerto, to be played by Matthew Trusler and the SSO at the City Hall concert, followed by a three-concert tour of China in August by the National Youth Orchestra of Scotland, with conductor Rory Macdonald and Danny Driver the soloist in Chisholm's First Piano Concerto, 'Piobaireachd'. And in June the Cottier Chamber Project will promote the world premiere performance of the first fully orchestrated version of Chisholm's 45-minute chamber opera, Simoon, whose re-creation is a story in itself.