[en] We have fabricated and tested a total of six single cell niobium cavities, made from single crystal, high purity niobium. Two of the three cavities of the TESLA shape (1300 MHz) were made from Heraeus niobium by extending a smaller single crystal by rolling and annealing steps; the third cavity was made by spinning from CBMM material. The three other cavities of the scaled 'Low Loss' (LL) shape (two) and 'High Gradient' (HG) shape (one) resonated at 2.3 GHz and were fabricated from 'as received' single crystals, both from Heraeus and CBMM niobium. After appropriate surface treatments by buffered chemical polishing and electropolishing most cavities performed quite nicely and peak surface magnetic fields of ∼ 160 mT or above corresponding to accelerating gradients between 38 MV/m and 45 MV/m were reached. This paper reports about the performance of these cavities.