Many Hal Leonard songbooks are available on Kindle Unlimited. If you already pay for Amazon Prime or Kindle Unlimited, you can "borrow" the book for free. You read it on a tablet (the same as a PDF) and it vanishes when you cancel the subscription—no copyright infringement involved.
Beyond the law, PDFcoffee is not a secure platform. Because it relies on anonymous uploads, users frequently report: hal leonard pdfcoffee
Short answer: Yes, in almost all cases.
Hal Leonard owns the copyright to every arrangement, transcription, and method book they publish. When you download The Real Book (6th Edition) or Guitar Aerobics from PDFCoffee, you are accessing an unauthorized copy. This constitutes copyright infringement under U.S. law (Title 17) and international copyright treaties. Many Hal Leonard songbooks are available on Kindle Unlimited
What about "educational use" or "fair use"?
Many musicians believe that using a PDF for personal practice qualifies as fair use. It does not. Fair use is a legal defense, not a right. It typically applies to criticism, research, news reporting, or limited excerpts (e.g., quoting two bars in a scholarly article). Downloading an entire 200-page Hal Leonard songbook for free is not fair use. Preview Viewer
PDFCoffee is not a secure, vetted platform. Many uploads contain hidden scripts, tracking pixels, or links to malicious sites. Music teachers have reported downloading "Hal Leonard – Guitar Chords.pdf" only to find their computers infected with adware or keyloggers.