Apex domains cannot have CNAME records.
Question and response
Question
dig dns.songnetworks.se. NS
Answer
dns.songnetworks.se. 5 NS c.dns.tele2.net.
dns.songnetworks.se. 5 NS b.dns.tele2.net.
dns.songnetworks.se. 5 NS a.dns.tele2.net.
Authority
The response has no authority records.
Additional
c.dns.tele2.net. 5 A 130.242.124.20
c.dns.tele2.net. 5 AAAA 2001:6b0:7:124:0:0:0:20
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0