arecordmidi: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/arecordmidi - from package: alsa-utils

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/arecordmidi - from package: alsa-utils

You may install the required package with command apt-get install {package}

Error in other languages:
arecordmidi: bevel nie gevind nie
arecordmidi: comandă negăsită
arecordmidi: comando não encontrado
arecordmidi: commande introuvable
arecordmidi: command not found
arecordmidi: käsku ei ole
arecordmidi: không tìm thấy lệnh
arecordmidi: komanda nerasta
arecordmidi: Kommando nicht gefunden.
arecordmidi: kommandot finns inte
arecordmidi: komut yok
arecordmidi: nie znaleziono polecenia
arecordmidi: níor aimsíodh an t-ordú
arecordmidi: no se encontró la orden
arecordmidi: no s'ha trobat l'ordre
arecordmidi: opdracht niet gevonden
arecordmidi: parancs nem található
arecordmidi: perintah tidak ditemukan
arecordmidi: príkaz nenájdený
arecordmidi: příkaz nenalezen
arecordmidi: команда не найдена
arecordmidi: командата не е открита
arecordmidi: 命令找不到
arecordmidi: コマンドが見つかりません