How to add music/ audio to text/ mms messages on iPhone 5?
There is not a way to add audio/ music to text/mms messages similar to adding a picture.
iPhone 5, iOS 6.1.4
To a standard SMS text message, no there isn't. For MMS it would depend on what multimedia your carrier supports. For anything that is not storted in the Photo app (images, video files), you add them to the Message using the camera icon. For anything else, you would start in the app that contains the file, and use the Share function (if available). The Voice Memos app does this for example. Third party apps would vary in terms of having this feature and how it is accessed.