Musicians have an extraordinary opportunity today to develop new approaches to composition that would have been unthinkable a few years ago. Imagine if you could play a musical instrument with signals detected directly from your brain. Would it be possible to generate music representing brain activity? What would the music of our brains sound like? These are some of the questions addressed by research into Music Neurotechnology , which is an emerging field at the crossroads of music, technology and neuroscience. There has been a great number of very interesting initiatives within the last decade or so to sonify brainwaves, some of which might indeed be useful for creative musical purposes. Also, the burgeoning field of Brain-Computer Music Interfacing (BCMI) is developing powerful methods to generate music in real-time by means of brainwave signals some initiatives of which are even looking into harnessing the potential of biomedically uncertified low-cost equipment for BCMI applications. However, in this chapter we discuss an approach that goes beyond sonification of brainwaves and BCMI. We introduce algorithms that we have been developing to compose orchestral music off-line with fMRI brain scans. The chapter is concerned with the impact of Music Neurotechnology to the field of Computer-Aided Composition (CAC). As we are not concerned with real-time interaction here, we have an opportunity to take advantage of the fMRI brain scanning method. This method is deemed too cumbersome for real-time applications, but considerably more powerful and informative than EEG (electroencephalogram) scanning, which is the method used in sonification and BCMI research. The composition methods introduced below were developed in OpenMusic, originally to generate materials for two symphonies by Miranda: Symphony of Minds Listening (2013) and Corpus Callosum (2015). And they were subsequently used to compose Shockwaves (2015) a violin concertino for orchestra. The discussions in this chapter will be mostly in the context of Symphony of Minds Listening and Corpus Callosum . We begin the chapter by briefly introducing Miranda’s approach to composing with the aid of computers, focusing on using algorithmically generated materials. Then we introduce the compositions Symphony of Minds Listening and Corpus Callosum. Next, we focus on the technical details of collecting and handling fMRI data, followed by an overview of the OpenMusic patches that we developed for this project and an explanation of how ATO-MS was used to generate orchestrations based on fMRI information. The chapter ends with a brief concluding discussion and acknowledgements to contributors and sponsors.