Re-listening to the episode, they were right about "Abacab" (not a bad song at all, especially miserable Tony's synth work). Also, Marion's "Sayonara Monsieur Kung Fu" is really good and a perfect example of turning one of the shittest songs ever released into a really enjoyable and catchy romp - maybe the lyrics are still terrible (my French is still at Year 11 level) but that lovely lilting French voice improves things drastically.
Also, I'm starting to get slightly obsessed with that Chi-Lites song from the '76 episode. Fucking TUUUUUNE!