Sidney Bechet believed it was because Keppard was a "good-time guy" that he refused the Victor Company's offer to make the first jazz recordings while he was still playing with the Original Creole Orchestra. In other words, he simply didn't want to make the recordings because the Victor Company represented big business and commercialization. Thus, if Keppard had agreed to make recordings for them with the Original Creole Band, the music would no longer have been for pure enjoyment but would have been turned into a commodity.

In the Victor Company files, there is a listing for an unnumbered test recording for a song called "Tack 'em Down" made by the "Creole Jass Band" on December 2, 1918 nearly two years after Keppard's first performance in New York. This recording may have been Keppard and the Original Creole Band.

The first recordings of New Orleans/Dixieland jazz came out in the 1920s, nearly two decades after the "hot" New Orleans sound and style had first been developed. By the time musicians of color like Freddie Keppard were recording, the Original Dixieland Jazz Band, an all-white band, had already made the first jazz recordings and had dominated the market for jazz recordings with their million-dollar hit "Livery Stable Blues." The ODJB's rendition of "Livery Stable Blues" came from a song Freddie Keppard performed. According to Keppard's contemporaries, the barnyard effects in the ODJB's version were jokes. As Mutt Carey, a fellow New Orleans trumpeter recalled, when Keppard was feeling good, "he'd get devilish sometimes and he'd neigh on the trumpet like a horse" to be humorous.

Musicians from Keppard's time who had either worked with him or heard him play praised his technical abilities and creativity. Mutt Carey, while respecting King Oliver, spoke of Keppard as the king of New Orleans jazz, calling him the best cornetist before Louis Armstrong.

Freddie had a lot of ideas and a big tone too. When he hit a note you knew it was a hit. I mean he had a beautiful tone and he played with so much feeling too. Yes, he had everything: he was ready in every respect. Keppard could play any kind of song good. Technique, attack, tone, and ideas were all there. He didn't have very much formal musical education but he sure was a natural musician. All you had to do was play a number for him once and he had it… he was a natural! When Freddie got to playing… he was no freak man like Joe Oliver. Freddie was a trumpet player anyway you'd grab him. He could play sweet and then he could play hot. He'd play sweet sometimes and then turn around and knock the socks off you with something hot.

— Mutt Carey

Willie Humphrey, a New Orleans jazz clarinetist, had also played with Freddie Keppard around the summer of 1919, at a time when half of New Orleans followed Joe Oliver and half the town followed Keppard. Humphrey recalled that Keppard was known as the musician's musician, Jelly Roll Morton's favorite musician, and "everybody's all-star."

Freddie had such beautiful tone. Such beautiful tone. Good ideas. Freddie played all over his horn. He had a different style altogether from Joe Oliver. Oliver was much rougher, you understand. Freddie was nice and light. Clear. You could be sitting right under him, and it would sound just as nice. But you could hear him two, three blocks away.

— Willie Humphrey

Jelly Roll Morton said of Freddie Keppard that he "had the best ear, the best tone, and the most marvelous execution I ever heard." Buster Bailey, a clarinetist who played with both Joe Oliver and Louis Armstrong, recalled that Keppard "could play as soft and as loud, as sweet and as rough, as you would want." Alberta Hunter, a blues singer and another artist who had been largely forgotten until she made her comeback in her eighties, also wondered why Freddie Keppard was often overlooked or unmentioned in many accounts of the histories of jazz. "You know," she reportedly said, "he doesn't get the credit he should get."

Some of the commentary on Keppard's playing, however, is admittedly quite contradictory. Of those who spoke of Keppard as a "freak player," most referred to him in this way because of his ability to utilize a variety of mutes and playing techniques, such as flutter-tonguing and half-valving. Others, however, insist that Keppard was a "much straighter player" than Joe Oliver. Additionally, while qualified listeners like Jelly Roll Morton were full of praise for Keppard's playing style, others like the younger Louis Armstrong is said to have described Keppard's playing as "fancy" (in an unflattering sense of the word).

Keppard made all his known recordings in Chicago from 1923 to 1927. The only recordings he is certainly on are three sides under his own name ("Freddie Keppard's Jazz Cardinals"), two with Erskine Tate's Vendome Orchestra, and a dozen with Doc Cook's Orchestra. These feature Keppard on second cornet. Second cornet was the logical and quite demanding seat for the premier cornetist in a two-cornet band, as evidenced by Louis Armstrong's role (one example of many) in similar sized bands and orchestras around the same period. His "Stockyard Strut" is an improvisation on the chords of "Tiger Rag". Keppard contributed to the Doc Cook recordings, where he plays the 'walking-talking' style of Stomp Cornet that pre-dates jazz by about a half generation. It follows ragtime by the same margin. Keppard may have appeared on a few other recordings; many more are often dubiously attributed to him. Keppard was widely imitated both in New Orleans and Chicago, including contemporaneous and highly regarded players such as Louis Panico and Frank Guarente. Other recordings Keppard made include songs titled "Salty Dog," "Adam's Apple," "Stomp Time Blues," and "Messing Around."

Several musicians with clear memories of Buddy Bolden said that Freddie Keppard sounded the most like Bolden of anyone who recorded. This is how many jazz historians propose that Keppard got his fame but also how he lost it. Keppard did not have a sound of his own and he came up in between Buddy, Oliver, and Armstrong. Keppard was extremely talented but was not unique. Others, like Lawrence Gushee, insist that Keppard did have a unique approach to playing the cornet, which simply became overshadowed by Louis Armstrong's powerful influence. Gushee describes Keppard as "frequently on top of the beat or [anticipating] it," making his "phrasing excitable, even tense." Whereas "Armstrong seems to favor extended four or eight-measure structure, Keppard [built] his units out of shorter modules" underscored by vibrato. Gushee also argues that Keppard used a much more "rapid vibrato, more like an ornament, that could be used anyplace in a phrase." Armstrong and Keppard met, but unfortunately, their first encounter was a letdown; instead of playing with Armstrong on the band stand, Keppard left in order to talk to customers, including an attractive blonde.

Many contemporaries said that either Keppard was past his prime when he recorded or that his recordings do not do him justice, as Keppard's health was already declining by the time he recorded in 1926. Even with the constraints, the recordings demonstrate that Keppard was a very proficient player and an adventurous improviser. Keppard's style is much more raggy and characterized by a "brusque and staccato style" compared to Oliver's blues-tinged style. While Oliver had more admirers, to some extent preference was a matter of taste. Jelly Roll Morton, Lil Hardin Armstrong, and Wellman Braud all thought Keppard superior to Oliver.

Keppard suffered from alcoholism and tuberculosis in his final years, although he continued performing despite illnesses. He was still playing loud in the early thirties in Chicago, although, according to contemporaries, no longer very well. By 1932, Keppard was restricted in his employment most likely due to his continued physical degradation. According to medical records, he was unable to work by December 1932. He died in Chicago in 1933, largely forgotten. However, trumpet player Bob Shoffner recalled that in 1931 when Louis Armstrong's band had been preparing to leave Chicago on a tour bus, Armstrong instructed the bus driver to stop in front of Keppard's apartment. The band went up the stairs to offer their greetings to the "old-timer."