Oh blimey, here comes one of those adagios...  get the Kleenex out...

This unfortunate idea seems to have arisen from that famous fraud of musical history "Albinoni's Adagio" (in G-Minor) - in fact a piece by Remo Giazotto based on seven notes (found on scrap paper) by the celebrated operatic composer Tomaso Albinoni (whose operas, of course, we never hear at all).  This wretched dirge has become a meme for wallowing grief-stricken wretchedness, and is therefore not played "ad agio" at all, but larghamente ("extremely slowly").

Ad agio means "at your ease", ie "a relaxed tempo", and doesn't mean "slow".  A notch down from adagio is grave, and only THEN do we finally reach "slow" (lento).

What other tempo-markings - either generally, or in specific works, do you find frequently ignored by performers who believe they know better than the composer?

We may like to consider the difference between tempo markings in the first and last movements of Mozart 40. Can anyone show them here, I don't have the score. I seem to recall they are two types of Allegro, but which is faster? (Hope that whets your appetite when I only have half the information to hand.)

And then there is the Adagietto in Mahler 5. what speed is that?

Indeed, let's clear up the -etto situation once and for all:  Allegro/Allegretto, Largo/Larghetto, Adagio/Adagietto - what's the difference? and do conductors really get it right?

My understanding of the -etto markings is that they imply a tempo one half-notch faster than without... so adagietto is a tiny bit quicker than adagio, etc...     is that what others think too?

Absolutely agreed about Barber, and moreover about his eponymous Adagio, which is wrung for every possible overwrought emotion into a largo or even a lento on most occasions.

Laaaaargo al factotum della citta, lar-go....

The ever-debatable Wikipedia gives (in the entry on Tempo) the following list of tempi (fastest at the top)

Prestissimo - extremely fast (200 - 208 bpm)
Vivacissimo - Very fast and lively
Presto - very fast (168 - 200 bpm)
Allegrissimo - very fast
Vivo - lively and fast
Vivace - lively and fast (~140 bpm)
Allegro - fast and bright (120 - 168 bpm)
Allegro Moderato - Moderately cheerful and quick
Allegretto - moderately fast (but less so than Allegro)
Moderato - moderately (90 - 115 bpm)
Andantino - Alternatively faster or slower than Andante.
Andante - at a walking pace (76 - 108 bpm)
Adagietto - Rather slow (70-80 bpm)
Adagio - slow and stately (literally, at ease) (66 - 76 bpm)
Grave - slow and solemn
Larghetto - rather broadly (60 - 66 bpm)
Lento - very slow (60 - 40 bpm)
Largamente/Largo - "broadly", very slow (40 bpm and below)

And by the way where has my avatar gone today?  It seems to come and go with a will of its own...  perhaps its on those occasions when I can't see my own reflection in the mirror...?

Wagner, universally.

All the evidence suggests that Wagner intended his music to move much faster than has become established practice.  There are reliable timings of Wagner's own performances of at least the overtures to his works, and these are often suprisingly quick - the Meistersinger prelude in a little over eight minutes, as distinct from the 10-11 minutes it is usually played at today.  And the Tristan prelude is marked Langsam und schmachtend, but is in 6/8 and is marked belebt as it approaches its climax (there are frequent expressive tempo changes marked in the score).  The rot seems to have set in in Cosima's Bayreuth.

There are conductors who can make slower Wagner work (Goodall, triumphantly so).  But, objectively, the evidence suggests it's wrong.

Very helpful I must say. What should also be borne in mind is that these indications aren't just to do with speed but with general expressive affect, particularly in the baroque period when they first became widely used. Some indications used at that time (eg. Affettuoso, very common in Telemann's instrumental music) don't really have any particular implications for tempo, others (eg. Allegro) seem to point to tempo as well as "tone of voice", while others (eg. Presto) seem straightforwardly connected to speed.

I may be mistaken, but I seem to remember a violinist friend of mine telling me that Bazzini's 'Ronde des Lutins' is actually Andante.

I can actually imagine it being sinister and like a 'Hall of the Mountain King' type work, rather than crazy franctic running around.

Anyway, he may have been pulling my leg.  I can't find a score to check.

Tommo

In the first movement of Beethoven's Moonlight sonata, the Adagio sostenuto direction is often taken to refer to the crotchets but it actually refers to the minims, the time signature being 2/2. That said, Solomon took it very slowly indeed on his recording and made it work wonderfully.

I get irritated by musicians who, observing that some of Beethoven's markings cannot be strictly observed, ignore them completely. The first movement of the Eroica symphony is marked Allegro con brio at dotted minim 60 (Beethoven meant this to apply to the opening bars, anyway). In his 1955 recording, Klemperer begins at 46! If his idea of Allegro con brio were transferred to either of two movements with the same marking - those of the Waldstein sonata or the C minor Piano Trio from Op 1 - I believe it would be found impossibly ponderous. But clearly there are many who love Klemperer's way with this piece. Give me Mackerras's 56 any day (but Richard Osborne likened the music at that speed to 'Mendelssohn with a headache').