According to Ego Trip's Book of Rap Lists there were 15 rap records released in 1979.
http://www.rocklistmusic.co.uk/ego_trip_page1.htm
According to DigitalDreamDoor there are also 15 rap records that were released in 1979 but there are a few differences. Ego Trip lists a few records that Digital Dream Door didn't list and vice versa.
https://digitaldreamdoor.com/pages/best_rap-oldsch.html
So I cross referenced both lists and after doing some research on Discogs and Youtube I've come up with what I believe is the most comprehensive list of rap records that were released in 1979. Every record I've listed has a Jpeg image of the label and an mp3 either on discogs.com or youtube.
One thing that I found interesting is that a lot of these records were released on The Sound Of New York Records, which was Spoonie G's label. Out of all the records released on that label Spoonie G probably had the best song and the longest lasting career.
Another thing I found interesting is that Mr Q released 4 records in 1979 and he's been erased from history. I've never even heard of him until a few days ago when I started this search. You'd think his name would come up more often.
Also, I found this clip on youtube about the first rap record that people insist is King Tim III. After doing all of this research I'd bet that some of these other records may have come first but there's just no way to prove it. King Tim III was by a popular band that charted on Billboard. Unless you have receipts from the record manufacturing factory or charted on Billboard there's really no way to prove when your record was manufactured and released to the public.
Rap Records From 1979
1. Rapper's Delight - The Sugar Hill Gang
2. King Tim III (Personality Jock) - Fatback Band
3. Rappin' and Rocking the House - Funky Four Plus One
4. Christmas Rappin' - Kurtis Blow
5. Superrappin' - Grandmaster Flash & The Furious Five
6. To the Beat Y'All - Lady B
7. We Rap More Mellow - Younger Generation (Grandmaster Flash &F5)
8. Rhythm Talk - Jocko
9. Rhymin' and Rappin' - Paulette and Tanya Winley
10. Rap-O, Clap-O - Joe Bataan
11. Lady D - Lady D
12. Jazzy 4 MCs - MC Rock
13. Rhapazooty in Blue - Sicle Cell and Rhapazooty
14. Spiderap/ A Corona Jam - Ron Hunt/Ronnie G & The S.M. Crew
15. Looking Good (Shake Your Body) - Eddie Cheba
16. Funk You Up - The Sequence
17. Street Talk (Madame Rapper) - Funky Constellation
18. Wack Rap - Solid C, Bobby D & Kool Drop
19. Rapper’s Delight/Rocker’s Choice - Xandu & Sweet Lady
20. Spoonin Rap - Spoonie G
21. Doctor Love & Sister Love - Doctor Love & Sister Love
22. Scoopy - Scoopy Rap
23. Tricky Tee Rap - Troy Rainey
24. Cloud One - Patty Duke
25. Gangster Rock - Little Starsky
26. Willie Rap - Willie Wood & Willie Wood Crew
27. Family Rap - Family
28. Party Rapp - Mr Q
29. The Rocketship - Jocko
30. Reasons To Be Cheerful part 3 - Ian Dury & The Blockheads
31. Ladies Delight - Mr Q
32. DJ Style - Mr Q
33. Rapping Time - Mr Q
34. Body Rock - Neil B
35. And You Know That - TJ Swan
36. Boogie Beat - Uno
Honorable Mentions:
Take My Rap...Please - Steve Gordon & The Koshers (1979)
Fly Guy - Fly Guy Rap (year unknown)
Big Foot Boogie - Brisko The Kidd (year unknown)
A Game Of Life - Lavaba & E. Mallison (year unknown)
Roller Rink Funk - Shift (year unknown)
Rasputin - Boney M (debatable - 1978)
Enterprise (Runaways Soundtrack -1978)
When its all said and done, the best records (imo) from 1979 are:
1. Rapper's Delight
2. Christmas Rapping
3. Rapping And Rocking The House
I would rank Rapping And Rocking The House #1 but it was too long. 16 minutes is cool but I wish they would have made a shorter version to give to radio stations. Rapper'd Delight worked because it fit the radio format.