In a letter to Councillor Von Mosel Beethoven explains that he has ‘often thought of giving up these senseless terms, Allegro, Andante, Adagio, Presto, and for this Maelzel’s Metronome offers the best opportunity’. The fact that Beethoven gave two differing metronome marks for his Symphony no. 7 leaves us with some uncertainty about the actual tempi he had in mind. But there is enough evidence in Beethoven’s letters to indicate the spirit intended in spite of the Italian terminology he finally used. Lionel Friend considers that Beethoven believed his tempo markings when he wrote them, while a performance could have changed his mind. In relation to Wagner he explains that the Flying Dutchman and Tannhäuser had metronome marks but Wagner soon realised that they didn’t work in performance. Leon Botstein makes the same observation about Schumann, ‘who made a number of changes’. He explains that Celibidache often took a slower tempo than the one marked because ‘he wanted to reveal the inner workings of a piece’. His conclusion is that metronome marks only tell you the composer’s intentions as useful indicators, not as an absolute requirement. He qualifies this view using Bartók as an example: ‘In performances, Bartók rarely conformed to his own metronome marks.’ In the twentieth and twenty-first centuries there have been many recordings which illuminate the flexibility which composers sometimes demonstrate in performances of their own works. Botstein’s view is that if the conductor’s performance is ‘persuasive, no matter what tempo, then it is correct’.

Joel Sachs refers to the two differing editions of Le Marteau sans maître, suggesting that in rehearsing the work initially the composer experienced the need for some slower tempi. We have to keep in mind that Boulez often chooses rapid tempi in performances of his own works, especially in later ones such as Sur incises. This is particularly characteristic of works which abound in grace-note flourishes. In a discussion with Boulez, Lionel Friend asked about the significance of irregular sforzandi within the grace-note groups. Boulez explained that they were there to ‘break up the rhythm and its regularity’. Friend considers this ‘breaking up of regularity’ to be the ‘destruction of a sense of pulse – something new’.