I'd like to find new pieces of music, resembling titles or a specific artist that I input into/specify for the program. The excessive choice of programs claiming this ability mystifies me. Which ones are most accurate, reliable, or trustworthy?
Update Nov 9 2014: OS: The app can operate online or on Windows, but other OS are fine.
Budget: Please prioritise free, online services, rather than paid ones.
What features must the application have? This program should offer several recommendations at once, unlike Grooveshark that does so one at a time. Indicia/indicators of the recommendations' aptness and relevance are preferred, but not necessary.
What sources to evaluate? What kind of output format? Alas, I don't know what sources would be used by such programs. Any readable output format is fine, so that I can research these pieces, but a text format would be ideal for saving suggestions onto the PC.