The most universally recognized lossy audio format in 2016 is MPEG-4 AAC audio.
Every device from the 21st century that can play audio video uses ISO/IEC 14496 MPEG-4. The playback decoding is done in hardware within the device rather than software on the general purpose CPU, which is very important in mobile applications where CPU resources are limited.
The lossy audio format in MPEG-4 is Advanced Audio Coding (AAC) which provides very good audio quality in very low bandwidth. It is not only universally supported in playback systems but also in production tools.
You can find out more about MPEG-4 AAC on the Advanced Audio Coding – Wikipedia page.
You can simply link to an AAC file with a hyperlink:
<a href="https://webmasters.stackexchange.com/audio_file.m4a" type="audio/mp4">Audio File</a>
… and then optionally, use JavaScript to replace that hyperlink at run time with an audio tag and/or sophisticated audio player if the browser supports that.
Your Web server is almost certainly setup to support MPEG-4 audio, but if not, you would want to have a line like this in your httpd configuration or htaccess file:
AddType audio/mp4 .m4a