In chamber music, an attacca is when the violist does not re-tune between movements. I’ve personally never experienced such a moment in a concert.
There is also the clarinet rule. Clarinettists do not really believe in attaccas, partly because mischievous composers have always demanded clarinet changes between attacca movements. It’s hard to feel to sorry for clarinettists, as trumpet players seem to be able to play the whole repertoire on a C or Bb trumpet. All clarinettists see it as their professional responsibility to try to do away with attaccas whenever possible, and to warn conductors of injury and possible musical calamity whan attaccas taken that aren’t in the score. Any time I announce an attacca, chances are it will be a clarinettist raising his hand to warn me of the potentially dire consequences of this act of madness.
However, the most important thing about attacca’s is to TELL THE ORCHESTRA- “I am not going to take 10 minutes to mop up and tuck my shirt in after the slow movement, but will instead be proceeding attacca to the Finale.” I was once playing cello in a marvellous American orchestra to remain nameless when the maestro, in a sudden moment of inspiration, finished the slow movement of Schumann 2 and launched attacca! into the finale. Caught completely unprepared, only about 15 string players were able to get their bows on the string for a feeble first bar of the finale, but worse, the poor clarinettist, who had spent his entire career warning conductors of the perils of clarinet changes in every work of the symphonic literature, was so shocked that he dropped his clarinet (which he wasn’t, in fact, changing), which proceeded to bounce down the stage on each level of risers, completely drowning out the meagre string section for the first couple of bars.
c. 2008 Kenneth Woods