You chose 3 fields where its very very hard to make a decent living...
Singer:
http://www.payscale.com/research/US/Job=Musician_or_Singer/SalaryHistorian:
http://www.payscale.com/research/US/Job=Historian/SalaryProfessor of History:
https://www.glassdoor.com/Salaries/professor-history-salary-SRCH_KO0,17.htmPolitical Scientist:
http://study.com/articles/Average_Salary_of_a_Political_Science_Major.htmlMy honest opinion in terms of job growth, availability of employment, salary, and potential for advance would be a political science degree with maybe a minor in statistical research. 2012-2022 job growth for political scientists is 22%. That's above average.