Amateur Radio

It's been too many years since the last time I thought about building antennas, so i'm a bit rusted: I think about installing a nylon cord between my house and my neighbours house (some 40 or 50 meters away) to put a dipole on the cord. Before I start calculating, what lambda fraction for which band I can get with that distance, I have another question: Would it be possible to attach 2 or 3 dipoles for different bands on the same cord? Or would that lead to unwanted resonances between the antenna wires, so I'd better get multiple cords installed, and mount one dipole on each cord?

On a side note: If you have better ideas or other advice, please tell me. Thank you :)