The madrigal singing session at the Welches' amateur music weekend is underway. Dixon has claimed to be able to sight-read music and the others have forced him to participate in the singing. Dixon lays low under the cover of another tenor and History department colleague, Cecil Goldsmith, for a song. Just as Dixon's lack of musical talent is about to be exposed in the following song, Professor Welch's son, Bertrand, arrives.
The madrigal group breaks up, and Dixon retreats to a corner to smoke and look at Bertrand's girlfriend, whom he immediately thinks is out of his league. Dixon strikes up a conversation with Margaret, and Bertrand and his girlfriend come over. Bertrand gives a witty speech about his work as a painter that annoys Dixon with its rehearsed quality. Dixon turns to Bertrand's girlfriend and addresses her as "Sonia Loosmore." In fact, Margaret's earlier information was mistaken, and Bertrand and Sonia Loosmore have recently broken up. Bertrand furiously accuses Dixon of deliberately provoking him and walks away with Christine.
Dixon and Margaret discuss the appealing beauty and unappealing snobbery of Bertrand's girlfriend Christine. Dixon walks off to check the recital schedule with Professor Welch and returns to find Margaret talking with Carol Goldsmith, a friend of theirs. When Dixon calls Bertrand's behavior rude, Carol and Margaret defend Bertrand, to Dixon's surprise. Carol explains that they have been friends with Bertrand since the previous summer.
Bertrand returns to the group and, in response to Carol's questions about Christine, reveals that Christine is the niece of Julius Gore-Urquhart, a famous art patron. Christine has arranged a meeting between Gore-Urquhart and Bertrand, as Bertrand is interested in a position as Gore-Urquhart's personal assistant. Margaret reminds Bertrand that the weekend on which Bertrand and Christine will return to the country to meet Gore-Urquhart is the weekend of the College's Summer Ball.
Christine returns to the group and Margaret praises Gore-Urquhart for his generosity. Bertrand begins to criticize the government for draining money from the rich. Dixon steps in with a comment endorsing socialism, and Christine and Bertrand react to Dixon's comment condescendingly. Bertrand will not let the discussion go until Dixon cedes his point, which Dixon refuses to do. Christine asks Dixon to stop talking "in that strain," because it irritates her. Just as the next recital piece is about to begin, Dixon insults both Christine and Bertrand. They are near the point of physical violence when Professor Welch returns and Dixon brushes past him out the door.
Chapter 4 first uses the plot device of a social gathering to bring all of the characters together, which serves to underscore the similarities and allegiances between the characters, and to create comedy by having the diverse personalities bounce off one another. The similarities and differences of the characters in this particular social gathering at Welch's house revolve around the idea of class differences, and how one's hobbies, clothing, manner of speech, and ideas mark one as being from a different social class. Dixon suspected in Chapter 2 that Ned Welch has invited him to the party to infuse a little "culture" into Dixon, but the chapter turns out to be more of a test than a lesson. Dixon begins the chapter at risk of exposure for being unable to sight-read madrigal music, and ends the party on the "wrong side" of a debate about social welfare. As always, however, Dixon is still our hero—we don't envy the rest of the Welch crowd because Dixon has so contemptuously described the madrigal activities, the cakes served instead of a proper evening meal, and Bertrand's pretentious accent.