There is a certain type of song that has offers a specific type of trap to the performer. These are songs in which the lyric makes an explicit commitment to a certain expressive quality or type of characterisation in such a way that really draws attention to itself if the performers’ musical rendition doesn’t quite achieve it.
The classic example is ‘I Got Rhythm’. If you don’t got rhythm, it shows. Similarly, if you ain’t got that swing, your performance of Duke Ellington’s classic is unlikely to be meaningful. Indeed, any song whose lyric describes one of its constituent musical elements is simultaneously telling the performers how they should sing it and telling an audience the criteria by which they should judge that performance.
These are the literal hostage-to-fortune songs. The more metaphorical type are the ones in which the lyric sets up a persona that is in some way remarkable or extraordinary, and thus places certain remarkable or extraordinary demands on the musical characterisation. ‘Running Wild’ is a good example (or, ‘Running Tame’ as I have come to think of it), as is ‘Red Hot’ (a.k.a. ‘Red Warm’).
The problem with hostage-to-fortune songs is not simply that you sometimes hear less-than-perfect performances of them. Most performances you hear have some flaws, after all, but that doesn’t stop them having entertainment value. The problem is that the gap between the song’s aspiration and its execution in performance can generate audience embarrassment. The gap suggests a certain lack of self-awareness on the part of the performers that makes the audience uncomfortable: ‘I can hear that you’re not very wild,’ thinks the listener, ‘so how come you don’t realise?’
This gap is often explained in terms of song ‘suitability’. But choosing songs suitable to the performing group is one of those things that sounds easy, but isn’t necessarily. The advice to pick a simple piece and sing it well, rather than makes a dog’s breakfast of a complex one is on the face of it sensible. But a song so simple it has no technical traps to fall into may well also lack the musical interest to generate an interesting performance. If the singers find the music dull, their voices sound dull too.
So the reason people choose to sing hostage-to-fortune songs is that they articulate a state the performers would like to aspire to. They want to feel hot or wild or rhythmic. They empathise with the song. But then, of course, empathising with the song is also what the audience wants to do, but they find they don’t know whether to empathise with the state reported in the lyrics or the actual performance they see.
I’m not saying don’t sing these songs – the world would be a poorer place without them for sure. But I am suggesting that you don’t use these songs as the vehicle to develop the skills or qualities they name in their lyrics. There are plenty of rhythmic songs that don’t have lyrics about rhythm you can use to hone your rhythmic skills – which you can then apply to Gershwin’s classic.