user49126: I was trying to run this library on Arduino Mega, using ESP8266 as replacement of Wifi Shield, as suggested on my older thread. 
The problem is, I got error in compiling, after with this code : 
#include <WiFiEsp.h>
#include <WiFiEspClient.h>
#include <WiFiEspUdp.h>


#include "AppleMidi.h"
APPLEMIDI_CREATE_INSTANCE(WiFiUDP, appleMIDI1);
....


exit status 1
'WiFiUDP' was not declared in this scope

if I modified the code into this : 
#include <WiFiEsp.h>
#include <WiFiUdp.h>


#include "AppleMidi.h"
APPLEMIDI_CREATE_INSTANCE(WiFiUDP, appleMIDI1);
....

I got this error instead

C:\Program Files
  (x86)\Arduino\libraries\WiFi\src\utility\server_drv.cpp:313:40: error:
  'WARN' was not declared in this scope
WARN("error waitResponse isDataSent");

                                    ^

exit status 1

Full code here at pastebin.
I was pretty much stuck now. Please help! :(
Thanks :D 

user37622: the WiFiEsp class for UDP is WiFiEspUDP
#include <WiFiEsp.h>
#include <WiFiEspUdp.h>
#include "AppleMidi.h"

APPLEMIDI_CREATE_INSTANCE(WiFiEspUDP, AppleMIDI);


49126: <p>I was trying to run <a href="https://github.com/lathoub/Arduino-AppleMIDI-Library" rel="nofollow noreferrer">this library</a> on Arduino Mega, using ESP8266 as replacement of Wifi Shield, <a href="https://arduino.stackexchange.com/questions/55753/is-there-any-easy-way-to-change-arduino-wifi-shield-to-esp8266">as suggested on my older thread.</a> </p>

<p>The problem is, I got error in compiling, after with this code : </p>

<pre><code>#include &lt;WiFiEsp.h&gt;
#include &lt;WiFiEspClient.h&gt;
#include &lt;WiFiEspUdp.h&gt;


#include "AppleMidi.h"
APPLEMIDI_CREATE_INSTANCE(WiFiUDP, appleMIDI1);
....
</code></pre>

<blockquote>
  <p>exit status 1</p>
  
  <p>'WiFiUDP' was not declared in this scope</p>
</blockquote>

<p>if I modified the code into this : </p>

<pre><code>#include &lt;WiFiEsp.h&gt;
#include &lt;WiFiUdp.h&gt;


#include "AppleMidi.h"
APPLEMIDI_CREATE_INSTANCE(WiFiUDP, appleMIDI1);
....
</code></pre>

<p>I got this error instead</p>

<blockquote>
  <p>C:\Program Files
  (x86)\Arduino\libraries\WiFi\src\utility\server_drv.cpp:313:40: error:
  'WARN' was not declared in this scope</p>

<pre><code>WARN("error waitResponse isDataSent");

                                    ^
</code></pre>
  
  <p>exit status 1</p>
</blockquote>

<p>Full code <a href="https://pastebin.com/K8b5J726" rel="nofollow noreferrer">here at pastebin.</a>
I was pretty much stuck now. Please help! :(</p>

<p>Thanks :D </p>
 37622: <p>the WiFiEsp class for UDP is <code>WiFiEspUDP</code></p>

<pre><code>#include &lt;WiFiEsp.h&gt;
#include &lt;WiFiEspUdp.h&gt;
#include "AppleMidi.h"

APPLEMIDI_CREATE_INSTANCE(WiFiEspUDP, AppleMIDI);
</code></pre>
