I still remember the first time I came across an appoggiatura. I must have been about six or seven years old and in a piano lesson (I really wish I'd practised more!) and there was this little quaver in front of a big quaver. When I asked what that meant I was told that I should play them both as semiquavers. I remember thinking, "Well why didn't you just write that then?", and I'm positive I didn't stop pestering my poor piano teacher for a proper explanation.
Decades later, having spent many hours exploring this mystery, the question still fascinates me. One day I'll write a book about it, but for now here's a video I made for the OAE's Illustrated Theory of Music Series.
More information about other interesting projects coming soon!