MONTREAL (CP) -- Arthur Fiedler, for 29 years conductor of the Boston Pops Orchestra, blandly says:  "I like rock and roll."
   And he believes many symphonies are not good music.  Some of them are "terribly boring".
   "People worry about us getting depraved musical tastes.  Nonsense."
   Mr. Fiedler says rock and roll "will have its vogue and then die a natural death.  It doesn't create teen-age problems.

   This year could well be the year of instrumental hits as was 1953 with songs like "Blue Tango," "Delicado" and Fandango."
   It could be the way back to the big band sound, although this trend now is different in one respect.  The big instrumental hits this month are done by small combo groups with a dash of progressive jazz apparent in all offerings.
   There is also a trend towards Dixie music.
   Let's look at the survey this week and find the instrumental sides.
   There's Mo Koffman's "Swinging Shepherd Blues" . . . Mo is a Canadian and he uses his quartette to fully present the cool sound.  Then there's the Dixie flavor evident in the new interpretations of W. C. Handy's immortal "Yellow Dog Blues" newly arranged by Johnny Maddox, Pete Fountain and Joe Darrensbourgh.
   Other instrumental sides take in all fields, the "Colonel Bogey March From the River Kwai" with Mitch Miller and Billy Vaughn's "Sail along Silvery Moon."
   In the rock vein there is "Raunchy," one of the first big instrumentals for the new year and of course Ray Connif's "Just Boppin."
   This could well be the prelude to band music on your hit parade.