After successfully installing stretch on a system, there was no /dev/dsp. I needed to play some mp3 files and so installed mplayer. The mp3's played and I also discovered /dev/dsp for the on-board sound chip and /dev/dsp1 for a USB card which began to work when used with an application I wrote that is a few years old and makes use of /dev/dsp.
I was thankful that the install of mplayer and several dependent libraries seemed to have restored the dsp devices so I powered down the system and have brought it up today to find that once again, no /dev/dsp. Something got turned on during the installation process that doesn't default to on. Where should I look as I can do that quicker than I can rewrite the application to do whatever you must do these days to speak to a sound device. The system has alsa-utils but I was under the impression that these days, one should not install alsa-base. As I reported, this system is capable of /dev/dsp but it seems to have lost it again. That is why I am confused. Thanks for any constructive suggestions. Martin McCormick