abc2midi: 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 Debian possible default full paths are:

/usr/bin/abc2midi - from package: abcmidi

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

Error in other languages:
abc2midi: bevel nie gevind nie
abc2midi: comandă negăsită
abc2midi: comando não encontrado
abc2midi: commande introuvable
abc2midi: command not found
abc2midi: käsku ei ole
abc2midi: không tìm thấy lệnh
abc2midi: komanda nerasta
abc2midi: Kommando nicht gefunden.
abc2midi: kommandot finns inte
abc2midi: komut yok
abc2midi: nie znaleziono polecenia
abc2midi: níor aimsíodh an t-ordú
abc2midi: no se encontró la orden
abc2midi: no s'ha trobat l'ordre
abc2midi: opdracht niet gevonden
abc2midi: parancs nem található
abc2midi: perintah tidak ditemukan
abc2midi: príkaz nenájdený
abc2midi: příkaz nenalezen
abc2midi: команда не найдена
abc2midi: командата не е открита
abc2midi: 命令找不到
abc2midi: コマンドが見つかりません