Sorry but this is incorrect.

Several fiddler friends of mine flew SAS early this past fall and were forced to check both of their fiddles and pay the fees. They were shocked and understandably upset. Luckily their instruments were not damaged but they spent the whole flight worrying about them. That is why I wrote to SAS, since I have an upcoming flight on SAS to Sweden.

While it may be true that people have gotten away with bending the rules in the past, they are no longer allowed to do so. SAS has implemented very restrictive new luggage policies (which they euphemistically call a "new baggage concept") and haved added high fees for additional bags.