In a landmark study, Frits Noske identifies the "musical figure of death" in Verdi operas as a purely rhythmic device that announces or predicts tragic death. Verdi, from his first to the last few operas, used this orchestral device, usually to signal death or in some cases thoughts of vengeance. The basic formula has two, three or four fast notes followed by a single long note all played on a single pitch. Its placement in the drama is at times surprising. For example, in Otello the device occurs almost exactly at the mid-point of the opera when jealousy begins to overtake Otello, long before he kills his wife and then himself.
Acording to Noske the "musical figure of death" occurs in Aida in Act I when the love triangle, Aida, Amneris and Radamès, appears together for the first time. The timpani sounds a variant of the device, three fast notes followed by a long note, when Amneris experiences her first hint of jealousy that Aida may be her reveal for the love of Radamès. I question Noske in the Act I example. To me, a more obvious use of the device occurs early in Act II, when Amneris outwardly appears friendly to Aida (see example below). The timpani alone signals the death motive three times. Amneris sings: "The battle's outcome is dire for your people...I share the mourning that weighs on your heart." On the surface it seems she is sympathatic to those who died in battle. Noske suggests that the false kindness of Amneris is revealed by the death motive, which anticipates Aida's death.
In Act IV in the trial scene, before Radamès is sentenced, his name is actually pronounced in the "musical figure of death" rhythm, Ra-da-mès, with the accent on the last syllable. Ramfis announces his name three times and the trumpets and trombones repeat the rhythm in a loud declamation. The sequence itself occurs two more times (three total). The significance of the sequence is increased greatly by the fact that it repeats three times. Thrice repeated means something special in Verdi operas. In Otello, for example, Desdemona says "morta" three times after three knocks at the door, and Otello kisses Desdemona three times on three occasions before he finally kills her.
To Verdi the drama was all-important, and he used every means to make it understandable on many levels. The most obvious is that of the text, but on a different level, the orchestration and his use of orchestral devices helps communicate that which words cannot communicate alone. The "musical figure of death" is such a device.