The date of this recording session is unknown, but it was held sometime between September 12 and 16 1954.

RCA received tapes from Sam Phillips in December 1955, and where no tapes existed they used dubs from Sun singles for their masters (see below).

The masters of 'Tomorrow Night' and 'I'll Never Let You Go (Little Darlin')' were found on the same RCA tape copy, made in 1956, meaning that both are likely to have been copied from Sun box #7. These are usually believed to have been recorded in September, 1954, but Lee Cotten's assumption based on aural evidence goes against this. Cotten writes in the second edition of the book All Shook Up - Elvis Day By Day from 1998, that these three songs share the same tape delay echo that are not found on other recordings at this time.

The incomplete outtake of 'I'll Never Let You Go (Little Darlin')' as released by RCA comes from a copy of the Good Rocking Tonight LP (Bopcat 100). A recent new transfer of the original master tape has revealed that the dialogue previously thought to come from before the outtake of 'I'll Never Let You Go (Little Darlin')' actually comes from before the alternate version of 'Blue Moon Of Kentucky' (July 7 1954), which can be found on the release by Follow That Dream of the ultimate Sun collection - A Boy From Tupelo.

The two incomplete outtakes and the master of 'I Don't Care if the Sun Don't Shine' were finally mastered from the original(?) tape on Sunrise in 1999. All previous RCA/BMG releases came from a copy of the Good Rocking Tonight LP (Bopcat 100). Stereo clicks could be heard between the takes. These recordings were later re-issued on Good Rockin' Tonight (Bopcat 101) in April 1983. Note that the complete version actually is the master. The sound quality of the second Bopcat LP implies that the tape used could be first generation. The same song sounds extremely noisy and distorted on the 50s Box. It could be 2% too fast as well. RCA never received the master, but used a tape transfer of a SUN 78 RPM.

'Just Because' is available in complete form for the first time on FTD's A Boy From Tupelo set, where on all previous releases the intro was clipped. How FTD did this was to use a small part from 'Good Rockin' Tonight' to reconstruct the intro of 'Just Because'. The same edit was also used on The Complete Works 1953-1955 by MRS and the 2017 Sony re-release of the first two RCA albums Elvis Presley / Elvis.

In Ernst Jørgensen's A Life in Music it can be found that Sholes' notes indicated that RCA received 1 take of 'Satisfied', 10 takes of 'I'll Never Let You Go (Little Darlin')', 3 takes of 'I Don't Care If The Sun Don't Shin'e, 17 takes of 'Just Because' and 2 takes of 'Good Rockin' Tonight'. According to the same source, a slow version of 'Just Because' was recorded after the master. If so, this would explain why one version out of three of that particular song was mentioned by name instead of RCA matrix number.

In March of 2007, Sony decided to go through all of Elvis' masters. They retransferred everything and remastered all tracks including repairing as many clicks, pops, bad edits and dropouts as they could. They have used these newly mastered recordings on their new releases since 2007 including budget soundtracks, Legacy releases, the 30 disc Complete Elvis Presley Masters collection and the Franklin Mint package. These 2007 remasters were not used on FTD's A Boy From Tupelo, the masters were all remastered again from scratch on that set.

Thanks to Gary Hibbs for identifying the splice on the intro of 'Just Because' on FTD's A Boy From Tupelo.
Thanks to Kevan Budd for the Doug Poindexter information.

Elvis At Sun - Restoration (Courtesy of 'Master & Session')

The 50s Box digital masters of the nice 1956 RCA tape copies of 'Tomorrow Night' and 'I'll Never Let You Go (Little Darlin')' have been replaced by flat Sony transfers on Elvis At Sun - well suited here since these masters were finalized by Sam Phillips in the first place. This new transfer lacked a little high end and this was only compensated for by as much as the source could handle.

A completely different sound was recorded on the September 1954 session that produced the second Sun single 'Good Rockin' Tonight' (R&B side), 'I Don't Care If The Sun Don't Shine' (C&W side) and the rejected master 'Just Because', to be used for the first RCA LP in 1956. The early generation master tape of 'I Don't Care if the Sun Don't Shine' has finally been identified as a recovered master this time of course and the glitch is repaired as good as could be done. A pitch analysis implies that the recovered tape runs a little too slow on Sunrise, according to Scotty Moore's highly accurate guitar tuning during the Sun days. This observation is in accordance with the pitch of original Sun single, but yet Elvis' vocals may sound slightly too fast. On Elvis At Sun the pitch has been set to that of the original Sun single and the tuning of Scotty's guitar since most threads point in that direction. 

On Elvis At Sun 'Good Rockin' Tonight' is from a new Sony transfer from the recently found RCA 30 ips tape. 'Just Because' is a Sony transfer as well, but from the only, badly filtered, 1956 RCA copy that exists, apart from the album master of LPM 1254. Regardless of the now existing, best sources of each of these songs, traces of the same original tape curve problems are evident on all the three uptempo September 1954 recordings. They were recorded with way too much signal in the high end, especially in the 16 kHz region and with too little signal in the lower, so important 100-200 Hz region. Possibly a noise reduction curve on top of the NAB curve, or simply poor calibration, but it should be pointed out that this 16 kHz peak can be identified on some other Sun artists recordings between late 1954 and early 1955. 

RCA must have detected this but missed the target a little and filtered more in the 14-15 KHz region instead on 'Good Rockin' Tonight', which is close actually and not a problem today. On 'Just Because', RCA filtered out just about everything in the 9-10 kHz region, where there were no problems at all, leaving a black hole sacrificing much of the damped acoustic guitar that was recorded via the reverb tape machine. On Elvis At Sun all three songs have been calibrated with 16 kHz reduction and just a slight lift of the 100-200 Hz to compensate a little for what is considered to have been lost in the first place due to the wrong tape curve calibration. The black hole on 'Just Because' has been carefully raised, but not all the way of course, while the 14-15 kHz reduction on 'Good Rockin' Tonight' was found best left untouched after several blind A-B tests.