This is the 8402nd most frequent Russian word.
мэнсону
The word "мэнсону" is not standard in Russian, but it may refer to the name "Manson" in a specific grammatical case (dative or prepositional).
'Мэнсону' serves as the dative subject of the verb 'предложено,' referring to the person being offered an opportunity.
Мэнсону было предложено выступить на конференции.
Manson was invited to speak at the conference.
In this sentence, 'Мэнсону' is the dative form of a proper noun, indicating the indirect object to whom the song is dedicated.
Я слушал песню, посвящённую Мэнсону.
I listened to the song dedicated to Manson.
Here, 'Мэнсону' is again the dative form, used to show the recipient of the action (receiving the letter).