Old thread, but if anyone else looks here, it can be done in Audacity with Lame MP3 encoder installed. File > Import > Audio.. Select all the files and click Open to import them into Audacity. CTRL-A in Audacity to select all imported tracks. Tracks > Align Tracks > Align End to End Tracks > Mix and Render This will merge all the tracks, and now you can File > Export Audio... and select the settings you want to create your Single MP3. There will be no chapters with this method More on reddit.com

I saw there was already a comment thread on FFmpeg, but thought I'd start a new one with a bit more specifics, since the other one kind of seemed a bit ambiguous. So, FFmpeg actually has 3 official modes of concatenating audio, by using a demuxer, a protocol, or a filter. The filter requires re-encoding, so we won't mention that. The demuxer and protocol don't re-encode, so we'll focus on those. The most common method is probably the demuxer. I don't personally recommend it in this case, and I'll get into why later. But the reason why using the demuxer is so common is because it's a lot easier, because it actually has it's own separate scripting context specifically for it, the "ffconcat version 1.0" format. So, most people just use it because it's easier and they can just basically copy and paste the paths into a list and call it a day. In this case, I'd actually highly recommend using the protocol. The demuxer works on the stream level, so it unwraps the container and parses the audio stream. So, there's no re-encoding, but there could potentially be a slight gap introduced between the streams that's noticeable if you're trying to loop things or have a seamless transition from one audio to the next, like if you're combining short audio segments from an online audio stream you captured. The protocol, on the other hand, actually works on the file level and doesn't even actually parse much, it literally just chops out the stream without parsing it and just puts them together. So, there's no gap and it's entirely seamless. I actually have a script that does exactly what you're asking already and this is the method I personally use and have had the best results with. NOTE: Now, this should probably go without saying, but I just want to make it absolutely clear that both the demuxer and protocol do require that the audio specs of the streams be exactly the same. You can't just combine streams of different specs, like different sample rates or different codecs, bit depths, etc., without re-encoding, there's no way around that. They have to be encoded with the same specs if you want to concat them without re-encoding. And in the case of the protocol, since it works on the file level, it does require that all of the files/containers also be the same. The demuxer can actually jump between different file/container types, as long as the audio streams inside those containers are of the same specs, as mentioned previously. So, as long as all 10 files are all MP3s encoded with the same specs, the protocol is your best option. And whether you use the demuxer or protocol, you will also need to make sure you are in stream copy mode to further ensure nothing is re-encoded. In order to be in stream copy mode, use the `-c:a copy` argument, which tells FFmpeg to copy the audio streams without re-encoding. https://trac.ffmpeg.org/wiki/Concatenate More on reddit.com