(Pablo) If the bell vibrates surely it can only do so at one frequency which may well not be the note you are blowing. My trombone does this and the bell resonates just above D a ninth above Middle C. I can only get this note on a good day (a D-day, I call it) but you can excite the resonance by playing the G below Middle C, just slightly sharp. But none of this affects the sound of the 'bone in its normal range.

BTW I hope the Covid hasn't done you any harm. I certainly don't want to get it myself, not at my age.

[Rosie]Without trying to labour the point, I think this shows the difference between quality of metals, as instruments respond very differently. Tried doing harmonics? Like playing a note and humming strongly the 5th, 10th or 12th above? Bones are particularly good for this. Horns OK, Weber even wrote them into his Horn Concerto.

Thanks for the Covid good wishes. As I am still here, and as good as ever, no, it didn't bloody well get me, despite my age. I'm sure it's the cabernet sauvignon that did it - excellent preservative.

(Pablo) Can't do those harmonics. However, I can do quite a good growl, something that goes down quite well in a trad band but would get you some funny looks if you tried it in a big swing band.

[Rosie] Eh? Since when was growl banned from big bands? I've written it into swing charts myself. Bubber Miley in Duke Ellington's band?

(Pablo) You certainly wouldn't put in a growl when playing ensemble but I agree it could easily be part of an ad lib solo. I've even tried it myself but not to any great effect.

[Rosie] No? Try the first 10 sec of this

[Pablo] I relate that music to not very good chocolate chip cookies (though, if given them, I won't refuse) because of this