“Bless you, child. Keep singing.” Such was the encouragement jazz vocalist Kim Nazarian received during a brief but unforgettable encounter with her idol, Ella Fitzgerald. Entire careers have been built on less.

At Blues Alley on Saturday night, Nazarian was clearly thrilled to honor Fitzgerald — and help cel­ebrate Jazz Appreciation Month — with the formidable support of the Smithsonian Jazz Masterworks Orchestra and guest saxophonist Phil Woods.

Nazarian’s assignment, of course, was about as unenviable as they come, given Fitzgerald’s nonpareil gift for swinging, scatting and exuding effervescent charm. But Nazarian held up her end of the bargain, displaying a voice powerful enough to pierce through blaring trumpets and agile enough to recall the seamless quality that made Fitzgerald’s recordings with the late guitarist Joe Pass so compelling and intimate.

There were times, however, when classic arrangements devised by Billy May (“Hooray for Love”), Count Basie (“ ’Deed I Do”), Paul Weston (“Cheek to Cheek”) nearly stole the show. As always, the orchestra drew from a broad palette of bright and muted colors, while several soloists, including pianist Tony Nalker and trumpeter Kenny Rittenhouse, added evocative touches. Guitarist Marty Ashby, in addition to quietly conjuring Pass’s elegant artistry, helped propel the swing passages with the kind of smoothly shifting, low-string motion perfected by Basie band guitarist Freddie Green.

Even before he stepped onstage, Woods, 79, was easy to spot in the packed house. Who else had earned the right to wear a ball cap embroidered with the title “NEA Jazz Master”? The reedman briefly accompanied Nazarian and the orchestra, adding lift to the custom-tailored finale, “Oh, Lady Be Good.” But his fluid, bop-bred alto was heard to best advantage during the big band performances of two original compositions that included a sleek, soulful and stirring rendition of “Goodbye Mr. Evans.”

The orchestra has hosted numerous jazz greats over the years, but this performance, oddly enough, marked its first collaboration with Woods. Here’s hoping he’ll be invited back to town soon to participate in a full concert that celebrates his long and distinguished career.

Joyce is a freelance writer.