Soothing Jump Blues is a derivative of Jump Blues

Soothing jump blues references the different vocal style used by Roy Brown when performing Jump Blues. Jump Blues used a ‘shouting’ vocal style interspersed in some songs and an intermittent ‘call & response’ format sometimes. The response could be a saxophone repeating the melodic line sung by the lead vocalist, or band members or audience. Roy Brown was a crooner and had schooled himself using Bing Crosby as a model. His innovation used a smoother vocal style, replacing the ‘shout’, thus the more soothing jump blues description which influenced Rock & Rollers like Little Richard.

Research shows the following:

Jump Blues is the bridge between R&B and Rock & Roll.

There are four descriptions below. Last description is connection to Little Richard who was influenced by Roy Brown, a Jump Blues innovator during Jump Blues and influencer of what was to come – rock & Roll. From Richie Unterberger at allmusic.com:

The currents of jazz and blues may have run closer together in the 1940s than they did in any other decade. One of the biggest offshoots of this cross-breeding was jump blues, a form that thrived in the late 1940s and early 1950s in particular. With its rhythmic swing, boisterous vocalists, and oft-lighthearted songs about partying, drinking, and jiving, it hasn't lent itself as extensively to critical analysis as styles like rural Delta guitarists or electric Chicago blues. During the decade or so when it thrived, however, it laid much of the groundwork for what became known as rhythm and blues, and thus by extension rock'n'roll.

What is Jump Blues? One of the major stylistic foundations of rock, "jump blues" was a hopped-up, hard version of R&B. From About.com

Jump blues music is up-tempo and lively blues music, usually played by musicians with horns – I’m not talking about the devil or Billy the Kid – ha ha, get it, Billy the Kid, I’m just too good for this place, anyway, I’m talking horn musical instruments not things sticking out from your head next to your ears. Jump blues music was really popular during the 1940′s and had a bit of a revival during the ’90′s too. From musicbase.org

The prime purveyor of jump blues and its most successful practitioner, Louis Jordan enjoyed enormous success, both in the R&B and pop fields, between 1942 and 1951.

By the second half of the '40s, jump blues had become the dominant form of black popular music. Among its successful practitioners were Joe and Johnny Liggins, Roy Milton and his Solid Senders with boogie woogie pianist Camille Howard, Amos Milburn, and in the '50s Italian vocalist Louis Prima with Sam Butera and the Witnesses.

When you draw up a short list of the R&B pioneers who exerted a primary influence on the development of rock & roll, respectfully place singer Roy Brown's name near its very top. His seminal 1947 DeLuxe Records waxing of "Good Rockin' Tonight" was immediately ridden to the peak of the R&B charts by shouter Wynonie Harris and subsequently covered by Elvis Presley, Ricky Nelson, Jerry Lee Lewis, and many more early rock icons (even Pat Boone!). In addition, Brown's melismatically pleading, gospel - steeped delivery impacted the vocal styles of B.B. King, Bobby Bland, and Little Richard (among a plethora of important singers). Clearly, Roy Brown was an innovator - - and from 1948 - 1951, an R&B star whose wild output directly presaged rock's rise. From history-of-rock.com
This explains the link to Little Richard