Can using graded scale help limit number of "Don’t knows"?

Let's say I want to ask a user wether she likes a song or not.

If I ask her to answer:

• Yes
• No
• Don't know this song

I guess there's a risk that she will choose the last option for songs she knows only a bit.

However, if I use grade scale and ask her to answer with one of the following options:

• Definitely yes!
• Maybe yes
• Rather no
• Definitely not!
• Don't know

I guess there will be fewer "Don't know" answers, because if a user knows the song only a bit, she will have a chance to "hedge" her answer and answer with maybe/rather answers.

Is there any research supporting my guess?