Computer-based systems, devices, and methods for automatically generating aesthetic chord progressions and key modulations in musical compositions are described. Known harmonic relationships are expanded upon to produce a much richer set of harmonic transition probability models compared to conventional music theory, and these models are leveraged by a computer-based musical composition system to generate new musical compositions and variations of existing musical compositions. Techniques for enabling a computer-based musical composition system to automatically determine when to introduce a key modulation, what key to module to, and what chord progression(s) to use within the new key are all described.

Described are systems, methods, apparatuses, and computer program products for wireless in-ear-monitoring (IEM) of audio. A system includes transmitter(s) configured to map orthogonal sub-carriers of a digital signal to narrowband receivers to form receiver-allocated audio channels, modulate the digital signal, and transmit the signal as an ultra-high frequency (UHF) analog carrier wave comprising the orthogonal sub-carriers to the nearby receiver. A narrowband receiver is configured to demodulate and sample the sub-carriers allocated to the receiver. Sub-carriers can be positioned orthogonal to one another in adjacent sub-bands of the frequency domain and beacon symbols and pilot signals can be iteratively provided in the same portion of the frequency domain for each channel. The receiver can use non-data-aided and data-aided approaches for synchronization of the time domain and frequency domain waveforms of the received signal to the transmitted signal prior to sampling the allocated sub-carriers.

A method of communicating musical sound control data over a wireless network that includes receiving a plurality of data commands formatted according to a MIDI protocol; assigning a packet sequence number to each of the data commands to form a plurality of historical data payload packets; storing the historical data payload packets in a buffer; receiving at a wireless interface device an acknowledgment message having a feedback sequence number; removing from the buffer selected historical payload packets of the plurality of stored historical data payload packets, each of the selected historical data payload packets having a packet sequence number that is the same as or less than the feedback sequence number, such that the buffer stores non-selected data commands, each of the non-selected data commands associated with a packet sequence number greater than the feedback sequence number; and transmitting the non-selected historical payload packets over a wireless network.