Roy Orbison Jr. and Wife Asa Welcome Baby No. 4

Roy Orbison Jr. is warming up his vocals for a few more lullabies. The musician and his wife Asa welcomed their fourth child last month, People reports.

According to the publication, the couple's son — named Sun Jakob Orbison — arrived Sept. 11 in Los Angeles weighing in at 8 lbs., 16 oz. and measuring 21 inches long. 

Sun joins big brothers Roy Orbison III, 7, Bo, 5, and 17-month-old Love.

"We want Sun to know his family’s story," Roy Jr. shared with People. "His name is inspired by the legendary Sun Records where rock and roll was born with his grandfather Roy Orbison, Elvis, Jerry Lee Lewis, Carl Perkins and Johnny Cash. He’s our little sunshine." 

Just before celebrating Mother's Day, the couple announced they were expanding their family.

And while three boys already made life an adventure, the musician said he would welcome more children with his wife.  

“I was in a dark, lonely place before I met Asa. But everything since then has led me to a place of light and happiness," he said. "I'm so impressed by my wife and once again reminded what a powerhouse she and all mothers are."