In one film, this actor's character uses a metronome while questioning a man playing snippets of Poulenc's Perpetual Motion No. 1. In that film, he plays a man who becomes suspicious of two former students who host a strange party with food served off of a trunk. In another film, his character becomes suspicious after a man leaves late at night with a sample case, and then later washes some knives and a saw at a sink. A third film sees his character become suspicious upon seeing Judy wearing a necklace said to belong to Carlotta Valdes, whose spirit supposedly forced Madeleine to jump out of a bell-tower. FTP, name this actor who appeared as Rupert Caddell in Rope, and as a wheelchair-bound 
In one film, this actor's character uses a metronome while questioning a man playing snippets of Poulenc's Perpetual Motion No. 1. In that film, he plays a man who becomes suspicious of two former students who host a strange party with food served off of a trunk. In another film, his character becomes suspicious after a man leaves late at night with a sample case, and then later washes some knives and a saw at a sink. A third film sees his character become suspicious upon seeing Judy wearing a necklace said to belong to Carlotta Valdes, whose spirit supposedly forced Madeleine to jump out of a bell-tower. FTP, name this actor who appeared as Rupert Caddell in Rope, and as a wheelchair-bound photographer and an acrophobic former policeman in Rear Window and Vertigo, respectively.
In one film, this actor's character uses a metronome while questioning a man playing snippets of Poulenc's Perpetual Motion No. 1.
James or Jimmy Stewart