If you are putting these together on a smartphone, look for these tools:

For more control over transitions (like crossfading), desktop apps are more reliable. : Import your files.

Free MP3 Joiner - Download and install on Windows - Microsoft Store

: A simple interface where you drag and drop files into your preferred order before downloading the final file. 2. Using Desktop Software (Best Quality)

To make the transition between "realistic" sounds or music clips sound natural:

: Supports adding files from your PC, Mac, phone, or cloud storage to merge into one track.

: A popular Android choice for simple trimming and joining. Steps for a Professional Result