sidplay: 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/sidplay - from package: sidplay-base

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

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