7. A system of conforming an audio input to a musical key, the system comprising: one or more processors; and a memory containing processor-executable instructions that, when executed by the one or more processors, cause the system to: receive an audio input; determine a musical key of the audio input; sequentially for each consecutive note of the audio input, determine a pitch value for a preceding note and a subsequent note and an interval between the preceding note and the subsequent note of the audio input, select a plurality of alternative subsequent notes for each subsequent note based on the determined musical key and the determined pitch value of the subsequent note, score each interval between each alternative subsequent note and each respective note of a selected plurality of alternative subsequent notes corresponding to the preceding note based on the interval between the preceding note and the subsequent note of the audio input, select a best interval for each alternative subsequent note based on the scored intervals, determine a probability of each alternative subsequent note following each respective note of the selected plurality of subsequent notes corresponding to the preceding note, and select a best-match note for each note of the audio input based on the best intervals of all of the plurality of notes of the audio input and the determined probabilities of all the plurality of notes of the audio input; and conform each note of the audio input to a frequency of each respective best-match note.
7. A system of conforming an audio input to a musical key, the system comprising: one or more processors; and a memory containing processor-executable instructions that, when executed by the one or more processors, cause the system to: receive an audio input; determine a musical key of the audio input; sequentially for each consecutive note of the audio input, determine a pitch value for a preceding note and a subsequent note and an interval between the preceding note and the subsequent note of the audio input, select a plurality of alternative subsequent notes for each subsequent note based on the determined musical key and the determined pitch value of the subsequent note, score each interval between each alternative subsequent note and each respective note of a selected plurality of alternative subsequent notes corresponding to the preceding note based on the interval between the preceding note and the subsequent note of the audio input, select a best interval for each alternative subsequent note based on the scored intervals, determine a probability of each alternative subsequent note following each respective note of the selected plurality of subsequent notes corresponding to the preceding note, and select a best-match note for each note of the audio input based on the best intervals of all of the plurality of notes of the audio input and the determined probabilities of all the plurality of notes of the audio input; and conform each note of the audio input to a frequency of each respective best-match note. 10. The system of claim 7 , wherein each interval is determined based on midi pitch range.