I need assistance in putting together a title for a music album. I came across the much used phrase "ad astra" which is so beautiful to me, and I wished to write something like "the sweetness of the stars", which google tells me is written as "dulcedinem ad astra". Is this correct? If not, how would it be written instead? Thanks in advance!
You should know that Google Translate is no good for Latin.
"Of the stars" would generally be expressed by a genitive plural form, astrorum. "Ad astra" roughly means "to the stars".
I don't think you should use the form "dulcedinem". Latin inflects nouns for their role in the sentence. "Dulcedinem" is specifically the form of "dulcedo" that would be used for the object of a verb. The subject of a verb would use the form "dulcedo".
The form of a Latin noun considered to be the default is usually the form used for the subject ("nominative"). Unless you have a specific reason to use another form, you should use the nominative when you're using a noun phrase in isolation, outside of a sentence.
So the correct grammar to express "the sweetness of the stars" with the words that you are using would be dulcedo astrorum.
You could also express this idea with other words. Latin has a number of words for sweetness. According to Lewis and Short, dulcedo is often used in metaphorical senses ("pleasantness, agreeableness, delightfulness, charm"), and somewhat rarely used in the literal sense of "something sweet to taste".
Another option would be suavitas, which also is often used broadly, in the senses of "pleasing to the senses" or "pleasing to the mind".