This is a question I get from so many clients and potential clients that have the misconception that only stock in a corporation, membership interests in an LLC, or partnership interests in a partnership are "securities." Under the Securities Act of 1933, a security is defined as:
...any note, stock, treasury stock, security future, bond, debenture, evidence of indebtedness, certificate of interest or participation in any profit-sharing agreement, collateral-trust certificate, preorganization certificate or subscription, transferable share, investment contract, voting-trust certificate, certificate of deposit for a security, fractional undivided interest in oil, gas, or other mineral rights, any put, call, straddle, option, or privilege on any security, certificate of deposit, or group or index of securities (including any interest therein or based on the value thereof), or any put, call, straddle, option, or privilege entered into on a national securities exchange relating to foreign currency, or, in general, any interest or instrument commonly known as a "security", or any certificate of interest or participation in, temporary or interim certificate for, receipt for, guarantee of, or warrant or right to subscribe to or purchase, any of the foregoing.
Notice the first word is NOTE. The words "EVIDENCE OF INDEBTEDNESS" are also used. Notes, bonds, and indebtedness in general are a form of a security, and as such, any offering involving them must be handled and scrutinized in the same manner as an offering for equity (stock...etc). This doesn't necessarily mean that you need a private placement memorandum (PPM) depending on the specifics of the offering, the types of investors you seek, or the securities law registration exemption you will pursue - but that is a determination that should be made by an attorney with experience in those matters.
So don't make the mistake of believing that debt instruments are not securities!