When the musical subject begins directly on the first beat of the measure, one beat before, given in the time of the following measures and in the position of the last beat in the measure, will suffice to assure a concerted and clean-cut “attaque.” The following measures, from the PRELUDE TO THE MASTERSINGERS by WAGNER, illustrate this principle.
(B) When the musical subject begins on the last beat of the measure, give the preceding beat, first. This beat should be less marked than those following.
Overture to Tannhäuser—Wagner
NOTE: Many modern conductors dispense with this preceding beat. However, it is extremely valuable in establishing the rhythm and helpful to less experienced orchestral or band players.