Plot: 3 Dog Night-three lead singers, four powerful instrumentalists - are big business in the USA: usually using rearranged songs by other writers, they notched up 12 gold records in three years, including eight LPs. Tonight they include 'Mama told me not to come' (Randy Newman), 'Just an old-fashioned love song' (Paul Williams) and 'Eli's Coming' (Laura Nyro)