I repeat - if you don't like the man's strings, don't take his money. Just because you don't like those choices doesn't mean you don't have a choice...
Free speech may be guaranteed, but it is not absolute. There are numerous instances where exceptions have been created, either by legislation, or by legal precedent.
Furthermore, while we do not have a right not to be offended, that does not give a free pass to the manufacture and distribution of material that is patently obscene.
A case in point is Mike Diana, a Florida writer/artist who, a decade ago, created a self-published magazine called "Boiled Angel." One particular issue, number 8, contained articles and stories so shocking and disturbing he was once considered a suspect in the Gainesville slayings. While that was eventually dropped, he was subsequently tried and convicted of creating and distributing obscene material. Despite the unusual harshness of his sentence (which included no drawing of any kind, which would be checked periodically, and no contact with anyone under the age of 18), it was nevertheless upheld on appeal.
Therefore, regardless of what you assert, the fact remains free speech is not absolute.
Period.