Notes about the RTTTL file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The RTTTL file type is primarily associated with 'Ring Tones Text Transfer Language File'. Ring Tones Text Transfer Language is a simple text-based format that you use to create ring tones that can be uploaded into your cell phone via various cell phone uploading techniques. For example, Beethoven's Fifth Symphony start could be encoded as:
Detailed information for file extension RTTTL:
Primary association: Ring Tones Text Transfer Language File
File classification: SourceCode
To change file associations press Windows Key
and then Apps and Features
> Default apps
> Choose default apps by file type
Invalid file associations could be the result of underlying issues within your Windows PC.