Raising a Toast : Thanks to thoughtful groupings of players at the West Coast Jazz Party, the musical conversation flowed like wine.

Like any good party, the first night of the three-day West Coast Jazz Party at the Irvine Marriott was a mix of new and familiar faces, fascinating dialogue and the occasional personality clash. Friday’s headliners gave strong accounts of themselves, while traditional jam sessions boasted more thoughtful, and therefore more successful, combinations of musicians than in previous years.

The party’s practice of grouping artists in mix-and-match sessions based on the shared language of the standard continued to produce fine, even brilliant exchanges. As jazz, moving into its second century, becomes more and more a repertory craft, these improvisationally rich outings underscore one of the music’s principal attractions: its spontaneous, as-it-happens creation.

Among the first-time participants making strong impressions were vocalist-pianist Karrin Allyson, guitarist Dan Faehnle, trumpeter Byron Stipling and drummer Sylvia Cuenca. Other standouts well-known to the nearly 500 in attendance--but new to the party’s lineup--included pianist Monty Alexander, saxophonist Bud Shank and trombonist Rob McConnell. Party veterans--including drummer Jeff Hamilton, flutist Holly Hofmann and saxophonists Rickey Woodard and Ken Peplowski--made their usual valuable contributions.

Alexander, replacing scheduled headliner Gene Harris (home in Idaho with a kidney ailment), brought much of Harris’ good-time feel and characteristic enthusiasm to his closing set. The Jamaican-born Alexander has a certain rhythmic playfulness to his sound, heightened here by the responsive play of drummer Hamilton (both Hamilton and Alexander, as well as absent pianist Harris, are veterans of bassist Ray Brown’s trios). Alexander even closed his set with a Harris standby, “The Battle Hymn of the Republic,” though done with his own rousing, percussive feel.

Before that, Alexander introduced “Just in Time” with stride-piano touches, played a soulful rendition of “Stand Up for Jesus” and delivered a crisp “Body and Soul.” He inserted a mischievous bit of “Chop Sticks” into a calypso number and built up a harmonic roar on a traditional blues number. The responsive support from Hamilton and bassist Andy Simpkins gave the set the innocent interaction of children at play.

Vocalist Allyson (who appeared at Steamers Cafe on Saturday) has earned comparisons to Diana Krall with her pure tones and heartfelt delivery. Unlike Krall, Allyson seemed at ease as she moved through “It Could Happen to You,” Billy Strayhorn’s “Day Dream” and an upbeat “Sunday in New York.”

Allyson showed scat ability on a bebop medley of “Orinthology” and “How High the Moon.” Her unison singing in tandem with guitarist Danny Embrey made for a nice resonance, and her willingness to expand beyond the usual jazz repertoire, most notably with the simple ballad-theme from the movie “Cinema Paradiso,” gave her performance decidedly modern airs. Her own piano accompaniment was of the Shirley Horn sort: direct yet moody, and never in the way of her voice.

The night’s opening jam sessions were formulated for success, and with only minor exceptions, minus the showboating that sometimes mar the results. Particularly musical was the pairing of guitarists Faehnle and Frank Potenza, backed by drummer Hamilton and bassist Luther Hughes. The two guitarists shared lead and accompaniment duties as if they’d rehearsed for years (it was the first time they had worked together), and the blend of their sounds made for some of the evening’s most magical moments.

A group that included flutist Hofmann and saxophonists Woodard and Shank emphasized the democratic nature of jazz, with the disparate sounds of Hofmann’s muscular flute, Woodard’s lusty tenor and Shank’s bop-styled alto finding common ground on “I Remember April” and others. ‘Round midnight, the party moved out of the banquet room and into the hotel’s lobby for a jam session led by Hughes, an event that saw such major figures as saxophonist Shank and trombonist McConnell playing on the same tune. Now that’s something that could happen only at an event like the West Coast Jazz Party.