Following is the programme of the Pop Concert at Symphony Hall tonight: 1.  March, "Merry Soldiers,"  Sabathil 2.  Overture, "Zanetta,"  Auber 3.  Waltz, "Morgenblatter,"  Strauss 4.  Selection, "The Serenade,"  Herbert 5.  Excerpts from "The Flying Dutchman,"  Wagner 6.  Waltz, "Snowballs,"  Ziehrer 7.  Entr'acte, Gavotte for String Orchestra,  Gillet 8.  Overture, "Le Roi d'Ys,"  Lalo Violoncello obligato, Mr. Josef Keller. 9.  Waltz, "Harlequin's Journey,"  Zach 10.  Largo,  Handel Violin obligato, Mr. Jacques Hoffman. 11.  Valse, "Coquette,"  Leoncavallo 12.  March, "Obersteiger,"  Zeller