I'd like to add something to the other answer, since there's more semantic distinctions to it. Proper nouns enjoy a spectrum here, ranging from the same inflective behaviour as common nouns have to becoming essentially uninflectable quotations used as noun phrases.
The criterion is an interaction of whether the noun phrase is grammatically transparent with the null-article and inflection rules for proper nouns. This depends on semantics (asterisks marking ungrammatical examples):
Phrase is transparent, and needs an article (because is an Ortsname):
*Der Anfang der "Alte Straße"
Der Anfang der Alten Straße
Phrase is transparent, but can be used with Nullartikel (since it is a kind of Produktname):
Der Bassist von "Würzige Melonen"
Der Bassist der Würzigen Melonen
Phrase is not transparent (ohne alone cannot be inflected as a noun), cannot be used with article (Produktname again):
Der Regisseur von "Oben"
*Der Regisseur des Obens
Phrase is not transparent, and must be used with article (Bergname):
Der Gipfel des K2(s?)
*Der Gipfel von K2
Note that if the band's name were Alte Straße, you would say der Bassist von "Alte Straße" as well!
Obviously, there are corner cases, e.g., I'd accept der Gipfel von Olympus Mons, even though that is obviously a mountain. Or, with Band names, there seem to be some exceptions (der Bassist der Toten Hosen is much preferred to der Bassist von "Tote Hosen", but: von "Fünf Achterl in Ehren" seems better than der Fünf Achterl in Ehren).