Missing Content - old iTunes in my new iMac

Hi,

My old MacBook Pro broke down and I had to replace it with a new iMac. I signed in into my same old iTunes account I use in other three devices and downloaded my purchased full Albums, strangely some of the songs cannot be downloaded and prompted me to repurchase them.

I rarely bought individual songs, I mostly bought complete albums.

Is there a way to re download without re-buying them?

Ps. I haven't had the time to take off my old hard drive and move all of my content into my new iMac.

Thanks.