How to vertical align the content of columns in beamer class

Question

I'm creating a beamer presentation in which I need to have two columns. In most of the frames one of them is dedicated to an image, but in other ones both of them contain text. The text looks like it is vertical aligned, which is usually good, but in some conditions, for example when the contents of the columns is noticeably different, it looks quite unpleasant (see MWE below). I'd like to align each column's content to the top. I tried with \hfill but I had no result.

Is there a way to manually set the vertical alignment of the column?

---

MWE

\documentclass{beamer} % grey border added with GIMP

\begin{document}
\begin{frame}
\frametitle{Frame title}
\begin{columns}
\begin{column}{.4\textwidth}
    \alert{A long content,}
    \begin{itemize}
        \item such
        \item as
        \item an
        \item itemize
        \item environment
        \item with
        \item several
        \item different
        \item items
    \end{itemize}
\end{column}

\begin{column}{.4\textwidth}
    \alert{A short content,}

    e.g. a note.
\end{column}
\end{columns}
\end{frame}
\end{document}

Answer 1

To align the columns at the top, it suffices to add [t].

\documentclass{beamer} % grey border added with GIMP

\begin{document}
\begin{frame}
\frametitle{Frame title}
\begin{columns}[t]
\begin{column}{.4\textwidth}
    \alert{A long content,}
    \begin{itemize}
        \item such
        \item as
        \item an
        \item itemize
        \item environment
        \item with
        \item several
        \item different
        \item items
    \end{itemize}
\end{column}

\begin{column}{.4\textwidth}
    \alert{A short content,}

    e.g. a note.
\end{column}
\end{columns}
\end{frame}
\end{document}