Forty Five Downstairs is one of the friendliest art galleries I've been to in Melbourne. Although it's a bit tricky to find, it's well worth a visit. Forty Five Downstairs is found by walking down some stairs, in the entrance at Cumulus.
Forty Five Downstairs Stairs Flinders Lane Melbourne
Go down the stairs, and straight through the door. You will suddenly find yourself in a much larger than expected space. This is the start of the gallery. It is set in two sections. There is a smaller gallery that is immediately to your right. The other gallery is direct in front of you after you pass reception. You will see the reception, and I do recommend at this point taking the time to sign up to their mailing list.
Forty Five Downstairs Entrance Flinders Lane Melbourne
The staff here are particularly friendly, and will happily chat with you if you want to. And likewise they are smart enough to leave you alone if that's what works for you.
Their exhibitions change every six to eight weeks, and they have very good taste in bringing in artists that are interesting, contemporary and eclectic. The gallery showcase artists from which the artist profits. So it really is art for artist's sake.