added Ubuntu 17.04 and alsa.conf notes; indirectly resolves #21 and c…

…loses #24.

README.md

@@ -44,11 +44,16 @@ What's hot, what's not?
 
 ### OS
 
-Now full functionality also on Windows 10 and macOS based systems.
+Now full functionality also on Windows 10 and macOS based systems.  
+
 
 ---
 ## NEWS
 
+### CHANGES 2017/09/XX:
+
+    - added notes for Ubuntu 17.04 systems and /etc/alsa/alsa.conf issues
+
 ### CHANGES 2017/08/XX:
 
     - changed DCR; renamed InputStateRaw() to ButtonStateRaw()
@@ -260,6 +265,7 @@ For compatibility with existing code, use
 
       import launchpad_py as launchpad
 
+
 #### Install directly from Github
 
 Instead of downloading the source distribution, you can directly install it from Github
@@ -448,6 +454,50 @@ So, if the "cue" page is active and you try to activate an LED in the "loop" pag
 will not be visible until you activate that page.
 
 
+### Ubuntu 17.04 or alsa.conf issues
+
+Several users reported errors related to alsa.conf file missing:
+
+    ALSA lib conf.c:3009:(snd_config_update_r) Cannot access file /etc/alsa/alsa.conf
+    ALSA lib seq.c:935:(snd_seq_open_noupdate) Unknown SEQ default
+
+If /etc/alsa/alsa.conf does not exist, you can create a symbolic link to where it resides on
+your system. Find it with:
+
+    find /etc /usr -name "alsa.conf"
+
+If that command can _not_ find the "alsa.conf" (a common place is /usr/share/alsa/alsa.conf), you
+probably don't have Alsa installed at all.
+
+In all other cases, you can create a symbolic link from /etc/alsa/alsa.conf to the reakl file
+(assuming /usr/share/alsa/alsa.conf here).  
+Warning: Double check whether /etc/alsa/alsa.conf _really_ does not exist first!
+
+    sudo mkdir /etc/alsa
+    sudo ln -s /usr/share/alsa/alsa.conf /etc/alsa/alsa.conf
+
+After that, you might experience that Launchpad.py cannot find any MIDI devices. The output from "lp.ListAll()"
+does not return anything.
+
+In this case, the default sequencer entries might be missing in your alsa.conf.  
+You might wish to add this to your alsa.conf:
+
+    #
+    #  Sequencer interface
+    #
+
+    seq.default {
+      type hw
+      hint.description "Added by experts. Source: Internet \o/"
+    }
+
+    seq.hw {
+    type hw
+    }
+
+Thanks to [MartinPaulEve][17] for pointing that out.
+
+
 ### For Mac users
 
 #### Mac Python and Pygame
@@ -1931,3 +1981,4 @@ FMMT666(ASkr)
 [14]: https://novationmusic.de/support/product-downloads?product=Launchpad+MK1
 [15]: https://twitter.com/FMMT666/status/871094540140240896
 [16]: https://twitter.com/FMMT666/status/891077439023087618
+[17]: https://github.com/FMMT666/launchpad.py/issues/24