Frank Sinatra music in public domain?

I would like to use a Frank Sinatra recording of a public domain song for an upcoming project. May I do this freely in the U.S.?

No. The expiration of a song's copyright does not inject any commercial recording of the song into the public domain. A master use license from the owner of the master recording (generally a record company) and often union re-use fees would be required before one could commercially exploit a particular commercial sound recording of a PD song.

Is it true that pre-1972 sound recordings are public domain?

The U.S. Copyright Act was amended in 1972 to provide copyright protection for sound recordings. While it is true that pre-1972 recordings are not protected under U.S. copyright law, it would be wrong to conclude that pre-1972 sound recordings are unprotected under law. Pre-1972 sound recordings are protected under various U.S. laws, including special state statutes enacted to protect record companies from piracy before the Copyright Act was amended to include sound recordings. As a result, post-1971 sound recordings are protected under statutes and common law legal theories. The U.S. Copyright Act preempts claims within its subject matter, but because pre-1972 sound recordings are not within its subject matter, those claims are not preempted, and state laws govern. Make no mistake, if you use a1960s Frank Sinatra recording owned by Capitol Records in your commercial or video production, you can expect a lawsuit, and while it will not be a copyright claim, you will nevertheless be liable for infringement under state laws.

The Copyright Act expressly provides that with respect to sound recordings fixed before February 15, 1972, all rights or remedies under the common law or statutes of any state shall not be annulled or limited by the Copyright Act until February 15, 2067. After that date, the Copyright Act shall preempt state claims, effectively divesting pre-1972 sound recordings of any available production as of February 16, 2067.

Because of this preservation of state claims, pre-1972 sound recordings enjoy longer proprietary rights protection in most cases than post 1972 sound recordings protected under copyright. For example, a recording from 1927 will be potentially protected under state law for 150 years!