QUOTE(Holz Gedeckt @ Apr 15 2009, 02:46 PM)

But I don't think your point was correctly applied here, as that marking signifies mezzo-staccato, which is not tenuto.
I
know that! What I meant was - and, being a teacher, I will concede that the fault lies with me for not expressing myself sufficiently clearly - if a tenuto mark
always means to make the note at least its full length, what do you think is intended when it's used in conjunction with a staccato mark?
I think it means to detach the note, but emphasise it slightly. The reason I mentioned mezzo-staccato was as an indication that it (tenuto plus staccato)
didn't mean that as there is already a combination of signs to indicate that manner of articulation.
Anyway, here's what Wikipedia says (and yes, I know Wiki isn't always authoritative):
"Tenuto can mean either hold the note in question its full length (or longer, with slight rubato) or else play the note slightly louder. In other words, the tenuto mark is sometimes interpreted as an articulation mark and sometimes interpreted as a dynamic mark. When it appears in conjunction with an accent mark, it is of course taken as an indication of articulation, and, conversely,
when it appears in conjunction with a staccato mark, it is taken as an indication of a slight dynamic accent. When it appears by itself, its meaning must be determined by its musical context."
I prefer to think of it as an 'emphasis' or 'stress' on the note, rather than an 'accent', but otherwise the definition concurs with my understanding of what can variously be meant by tenuto marks. Incidentally, it's also used in drumming notation to indicate an emphasis.