In 1954 when Decca released a five-record musical biography of Bing Crosby, the album included this inscription: "The voice of Bing Crosby has been heard by more people than the voice of any other human being who ever lived."

That claim may have subsequently been altered by history and technology, but the fact is, Bing Crosby remains Our National Singer. CBC celebrates this fact Sunday night with "Bing!" a 90-minute special that, bolstered by other CBS specials scheduled for the evening, makes Sunday night family night on TV again, like it was when Ed Sullivan rallied us for bears, opera stars and dance troupes.

"Bing!" will be seen on Channel 9 at 9 p.m., preceded by the 19th annual network telecast of MGM's 1939 movie classic "The Wizard of Oz" at 7 p.m. and by a new special, "Henry Winkler Meets William Shakespeare" at 5 p.m.

The Crosby special would be an entirely convival occasion were it not for the knowledge that just after the taping, March 3 at Ambassador College in Pasadena, Calif., Crosby, 72, fell from the stage and suffered injuries for which he is still hospitalized. A spokesman in Los Angeles said yesterday that Crosby is "getting along fine" and could conceivably be released from the hospital this weekend.

The 90-minutes is rife with pleasures and the inducement of happy memories, with Crosby proving uncommonly generous in sharing the spotlight at his own party. The highlights include a farily riotous "Accentuate the Postive" with Bette Midler, Midler and the Mills Brothers riding merrily roughshod over "Glow Worm," and a Crosby duet with Pearl Bailey that could stop any show ever staged in the history of the world.

Even the cross-quips with Bob Hope, inevitable though they be, come off brightly, although attempts by Crosby's young children to sing do not. We can suffer him this indulgence, however. In his 50 years in show business, which is what this show commemorates, Crosby has asked for considerably less homage than many of today's drab stars demand in a single season.

"Heny Winkler Meets William Shakespeare" - note the billing - finds the agreeable young actor who plays Fonzie on "Happy Days" attempting to de-stigmatize Shakespeare for young audiences. The language is nothing to be afraid of, they are told, and the play is still the thing. A tour in Stratford , Conn., shows how scenery and stage lights work.

But the scene from Shakespeare chosen to end the program is a dual duel from "Romeo and Juliet" in which both Tybalt and Mercutio are killed. The message to kids seems to be, Shakespeare is just as much fun as television is, because you get to see people drop dead.