Apex domains cannot have CNAME records.
Question and response
Question
dig songnet.fi. NS
Answer
songnet.fi. 5 NS ns1.songnet.fi.
songnet.fi. 5 NS ns2.songnet.fi.
songnet.fi. 5 NS ns3.songnet.fi.
Authority
The response has no authority records.
Additional
ns1.songnet.fi. 5 A 194.100.90.53
ns2.songnet.fi. 5 A 62.236.49.41
ns3.songnet.fi. 5 A 80.64.12.65
ns1.songnet.fi. 5 AAAA 2001:6e8:0:1:0:0:3:2
ns2.songnet.fi. 5 AAAA 2001:6e8:0:1:0:0:4:2
ns3.songnet.fi. 5 AAAA 2001:6e8:0:1:0:0:5:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0