This PASCAL funded pump-priming project aims to bring continuous and uncertain interaction methods into both brain-computer interfaces, and to the interactive exploration of song spaces. By treating the interaction problem as a continuous control process, a range of novel techniques can be brought to bear on the BCI and song exploration problem. EEG brain-computer interfaces suffer from high noise levels and heavily-lagged dynamics. Existing user interface models are inefficient and frustrating for interaction. By explictly taking the noise and dynamical properties of the BCI control signals into account, more suitable interfaces can be devised. The song-exploration problem involves navigation of very high-dimesional feature spaces. The mapping from these spaces to user intention is uncertain. Uncertain and predictive displays, combined with intelligent navigation controls, can aid users in intuitively navigating musical spaces. This work is in collaboration with the IDA group at Fraunhofer First and the Intelligent Signal Processsing Group at DTU.