Be aware that many of BlackRock closed end muni funds are leveraged.

In 2008 I purchased $50,000 of a BlackRock Califonria Muni which held bonds maturing in 2018 for a share price of $15.00 and paying 5% yield tax free. When the credit crunch hit in late 2008 the value of the fund shares dropped quickly due to the fact than much of the portfolio was leveraged. I sold at $10.60 a share and lost 1/3 of my investment. The fund bottomed out at $9.02 a share. So read the fine print and watch out for the "leveraged".