1) In a medium-size saucepan, sprinkle the gelatin over water and keep aside for 5 minutes to soften.
2) Stir continuously over a low heat, until the gelatin dissolves.
3) Remove from heat and stir in the grape juice concentrate.
4) Refrigerate for, 1 to 1 1/2 hours, until thickened but not firm.
5) In each of 6 dessert glasses, spoon a layer of gelatin mixture .
6) Thinly slice banana and layer on top of each gelatin layer.
7) Repeat the layers and endwith gelatin, until the banana and gelatin are used.
8) Chill in the refrigerator, until the gelatin is set.
9) Serve the Grape Banana Gelatin Layers chilled.