abcmatch: 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/abcmatch - from package: abcmidi

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

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