For a middle of the road nightclub entertainer during the rock era, Bobby Short was very well documented on record.

This was due to his long on-and-off association with Atlantic Records.

The New York-based label led by the Turkish brothers Ahmet and Nesuhi Ertegun and Jerry Wexler made its money on R&B music initially and rock eventually, but the Erteguns in particular were always jazz aficionados who frequented the New York clubs, and they could afford to indulge an affection for the suave Short, who held forth in a series of those clubs until he secured his permanent residency at the Cafe Carlyle in 1968, brightly declaiming the songs of Cole Porter, Noël Coward, George & Ira Gershwin, Rodgers & Hart, and others while fronting a piano trio.

For the most part, Short's Atlantic LPs can't have cost too much money to make, although his series of double-LP songbooks of the early '70s must have absorbed something in pressing costs, even if one of them, Bobby Short Loves Cole Porter, actually made Billboard's Top LPs & Tapes charts for a couple of months in 1972.

The compilation 50 by Bobby Short, released as both a four-LP box set and as a double CD (with slightly different sequencing, no doubt to even out the lengths of the LP sides) may have been the Erteguns' greatest indulgence, however, and a monument to their noblesse oblige as well as their love for Short.

Compiled by the artist with Nesuhi Ertegun (who produced most of Short's Atlantic LPs), the collection covers two decades of performances from the mid-'50s to the mid-'70s, which is to say from Short's own early thirties to his early fifties.

While it is roughly chronological, and shows the singer's voice changing from a pure tenor to a slightly more gravelly croon, the musical approach never changes.

That is not to say that the arrangements are always the same, however.

While the basic unit is the piano trio, there are solos by Short as singer/pianist, and there are occasional entries by small bands of various sorts as the music leans toward blues or '20s jazz.

The moods also vary, from light love songs to novelties to somewhat more somber fare.

But Short always maintains an artistic distance from his material; he is always presenting it rather than inhabiting it.

That means he tends to be at his best when the mood is upbeat, and especially when the words are witty.

The Porter and Coward songs come off better than anything else, although Lorenz Hart's lyrics are also heard to great advantage.

And anyone else who is capable of a humorous twist in his lyrics benefits from Short's approach, whether it's Ira Gershwin or E.Y.

"Yip" Harburg.

Although this is an album of highlights carefully culled from a large catalog, it also illustrates Short's less-sure feel for more contemporary fare -- he does his best with Randy Newman's "Simon Smith and the Amazing Dancing Bear," but there's a level of irony he never gets at, and in Stephen Sondheim's "Losing My Mind," he shows himself unwilling to plumb the depths of its bitterness.

Short simply isn't that much of an ironic or bitter guy, but he excels at the kind of humorous wordplay achieved by Ivor Novello on "And Her Mother Came Too" or any number of other songs on this generally brilliant career summary.