@@rolandbaldwinI think it was Bosco, Live at 3 followed by Dempsey's Den, which moved to NETWORK2 on the rebrand in 1988. Emmerdale Farm could have being airing on RTÉ2 with A Country Practice/The Sullivan's, they all moved to RTÉ1 on move of The Den to 3pm on Network 2, with Bosco also moving to Network2 at 2:30, RTÉ1's 1 O'Clock News was introduced around 1989 I think, with the intro of 12 to 1 in the 1990s.
It's "Serenade for Strings In C Minor, Op. 48 : II. Waltz - Moderato" by Pyotr Ilyich Tchaikovsky. It was used in the early 1980s as a startup theme for Channel Television, the smallest company in the ITV network in the UK, serving the Channel Islands.