Many time before internet Doubling Riders make international collaboration, we record some tracks and we send tape at others musicians, they join new tracks and send back and so on.
In every LP or CD of Doubling there is different collaborators in every track:

Riccardo Sinigaglia, Francesco Paladino, Pier Luigi Andreoni with:
Annarosa Cortellini, Paolo Pirato, Giampiero Bigazzi, Maurizio Dehò, Silvio Linardi, Chris Carrer, Tommaso Leddi, Rossana Maggia, Fabrizio Croce.