sudo apt update

sudo apt install build-essential cmake pkg-config libmp3lame-dev libshout3-dev libconfig++-dev libraspberrypi-dev libfftw3-dev librtlsdr-dev

RTL_AirBand Software: 

wget -O RTLSDR-Airband-5.0.0.tar.gz https://github.com/szpajder/RTLSDR-Airband/archive/v5.0.0.tar.gz
tar xvfz RTLSDR-Airband-5.0.0.tar.gz
cd RTLSDR-Airband-5.0.0

Let's Make A Build Dir And cd Into: 

mkdir build
cd build

Time To Make And Install:

cmake ../
make
sudo make install

Let's Edit The rtl_airband.conf File:

sudo nano /usr/local/etc/rtl_airband.conf

Paste In The Following, Starting With devices:
Remember To Update The Password For Icecast2:

devices:
({
type = "rtlsdr";
index = 0;    #RTL-SDR Number
gain = 32;    #Gain Setting
correction = 0;
mode = "scan";
channels:
(
{
freqs = ( 123.1, 119.0, 120.5 );        #Add Freq's Here
labels = ( "Tower A", "Tower B", "Tower Control"); #Label Update
outputs: (
{
type = "icecast";
server = "127.0.0.1";
port = 8000;   #Port Number Setting
mountpoint = "stream.mp3";
name = "Airband Voice";   #Name Of Your Choice
genre = "Air Traffic Control";
description = "My Local Air Traffic"; #Description Of Your Choice
username = "source";
password = "Password";   #Icecast2 Password
send_scan_freq_tags = false;
}
);
}
);
}
);

Start RTL_AirBand In Terminal:

sudo rtl_airband -f

Open Up A Browser To Listen And Use The IP Of The Pi With :8000/stream.mp3