Monthly dividend stocks might seem like a gimmick, given that most American stocks pay out dividends quarterly. But they provide a very real service to income investors - especially those who have reached retirement.

Capital gains can be fleeting, as we saw during last year's two brutal corrections, but a regular stream of dividends and interest can actually put the cash in your hands to pay the bills, whether the market goes up, down or sideways.

Unfortunately, most income investments are designed remarkably poorly for their task. Bonds generally pay semiannually (twice per year). That made sense back in the days when "coupon payments" were literally based on paper coupons, but it hardly makes sense in an era in which bonds are nothing more that electronic entries. And again, most stocks pay their dividends quarterly. That's nice, but it's hardly helpful when your bills come monthly.

It wouldn't be particularly prudent to make the monthly payment schedule your primary reason for buying a stock. Clearly, safety and growth prospects matter far more. But all else equal, a portfolio of monthly dividend stocks can give your portfolio a baseline of income to tide you over in those months when your bonds and regular quarterly dividend payers aren't paying.

With that in mind, here are 10 solid monthly dividend stocks and funds to buy. These are also mostly high-yielding investments, ranging from 3% to 15%.

STAG Industrial

STAG Industrial (STAG, $28.78) is a "boring" real estate investment trust (REIT), and in investing, boring is beautiful - especially in solid, payout-growing monthly dividend stocks.

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